Series 18: Logopolis

The Fourth Doctor is pacing around in the TARDIS Cloister Room, pondering thoughts of decay and entropy. As he and Adric prepare to leave, the large bell in the centre of the room begins to ring. This worries the Doctor, as the sound of the Cloister Bell is a sign of impending universal catastrophe.

To keep his mind off this, he decides to repair the TARDIS's chameleon circuit, which has frozen it into the shape of a police box. In order to do this, he intends to materialise the TARDIS around a real police box (thus disguising it), and then obtain its precise measurements in 37 dimensions. With these measurements, he will have the inhabitants of the planet Logopolis produce a mathematical calculation — a block transfer computation — to reset the circuit. However, the "police box" he materialises around is actually the TARDIS of the Master, who has survived their encounter on the planet Traken. When the Doctor materialises around the Master's TARDIS, a recursive loop of TARDISes within TARDISes is formed.

Meanwhile, an airline stewardess, Tegan Jovanka, is being driven to the airport by her Aunt Vanessa. After their car breaks down, Tegan decides to go to the "police box" for help, but finds herself lost in the TARDIS instead. The Doctor and Adric enter another police box in a duplicate TARDIS, but the Doctor, telling Adric to wait behind finds himself this time outside the box. He meets a number of policemen, who find the shrunken, dead bodies of Tegan's aunt and another policeman.

The police think the Doctor has something to do with it, but Adric creates a distraction, and allows the Doctor to escape. In the distance, a mysterious white-clad stranger watches the proceedings. Realising that the shrunken bodies are the trademark of the Master, the Doctor decides to materialise the TARDIS underwater, to literally flush him out. The Doctor misses the River Thames, however, and lands on a boat instead. The mysterious stranger appears here too, and beckons to the Doctor, telling him to go to Logopolis.

As the TARDIS arrives at Logopolis, Tegan finds her way to the control room, somewhat annoyed. She asks to know where her aunt is, and the Doctor, realising that she was the dead woman in the car, skirts the question. Once they exit the TARDIS, the Doctor asks the Logopolitan leader, the Monitor, for his help. The Logopolitans are able to model reality by pure mathematics — whatever they calculate can take physical form. However, block transfer computations cannot be calculated by machines, so to perform them, the Logopolitans do not use computers. Instead, they use a large physical array of Logopolitans, each muttering a line of calculations out loud and passing them on to the next.

However, unknown to the group, the Master has arrived on Logopolis, and has killed several Logopolitans, which disrupts the calculations for the TARDIS. When the Logopolitans produce the required computation and the Doctor attempts to enter it into the TARDIS, it instead shrinks the TARDIS to half its normal size and causes strange effects inside the ship.

The Logopolitans try to stabilise the TARDIS using sonic projectors to project a stasis field while the Monitor and Adric attempt to uncover the fault. Meanwhile, Nyssa has been brought from Traken by the Watcher, the mysterious white figure the Doctor spoke with. She is searching for her father. The Monitor and Adric work through the city and discover the shrunken bodies of three Logopolitans. Correcting the error this has caused, they bring the new computation to the TARDIS. Tegan holds the notes up to the TARDIS so the Doctor is able to read them through the scanner and correct the fault. The Doctor emerges from the now restored TARDIS, and admits to Tegan that her aunt is dead. Meanwhile, Nyssa finds the Master, whom she believes to be her father as he is inhabiting Tremas's body. The Master gives her a bracelet, which is actually a device which will allow him to control her actions.

The Master attaches a device to the sonic projectors and sets up a counterwave that brings silence to the Central Registry, preventing the Registers from making their calculations. He then goes to the Registry's control room (a replica of the Pharos Project on Earth, a radio telescope tasked to seek out signs of extraterrestrial life), and demands that the Monitor tell him what the true purpose of Logopolis is. The Doctor arrives with Adric and Nyssa, and Adric deactivates the Master's device, only for the Master to have Nyssa attempt to throttle him. Tegan restores the device, and the Master repeats his demand. The Monitor warns the Master that bringing Logopolis to a halt will cause universal disaster, but the Master replies that it is only a temporary effect, which he attempts to demonstrate by deactivating the suppression device.

However, the silence persists and the calculations do not resume. They go outside, and find all the Logopolitans dead, crumbling to dust, and the city itself collapsing. The Master thinks this is some sort of trick and tries to have Nyssa strangle the Monitor, but the control device ceases to function. He tries to increase the device's power, but this causes it to fall apart as local decay increases. The Monitor explains the situation: the universe had long ago passed the point of heat death. To stave off final collapse, the Logopolitans had been modelling a number of temporary Charged Vacuum Emboitments, like the one through which the TARDIS had been previously transported into E-Space. The excess entropy generated by the universe had been passing through the CVEs to other universes. However, The Master's interference has caused the CVEs to close and the universe is now dying at last. Realising that he has no other option, the Doctor orders his companions into the TARDIS, and agrees that he and the Master must work together if they are to prevent the universe's destruction.

As soon as the Doctor and Master walk away from the TARDIS, Tegan sneaks out and follows the Doctor, Master and Monitor back to the Logopolis control room. In the meantime, the Watcher takes the TARDIS, carrying Adric and Nyssa, out of spacetime. The Monitor reveals that they had been completing a program to make the CVEs permanent, and prepares to use it on one of the surviving CVEs, but entropy takes hold of him and he disintegrates before their eyes. The Doctor dismantles the computer and realises the program is stored in bubble memory that they can use with the real Pharos Project. The Doctor, Master and Tegan escape from Logopolis in the Master's TARDIS.

Adric and Nyssa watch helplessly in the Doctor's TARDIS as a portion of the universe is wiped out by encroaching entropy — including Traken. On Earth, the two Time Lords reconfigure the Logopolitan program and feed it into the Project's computers, but the Master points out that the transmitter is pointed away from the last surviving CVE. After speaking with the Watcher, Adric brings the Doctor's TARDIS to Earth as the Doctor and the Master run on foot to realign the dish. The Doctor's companions distract the guards and the two Time Lords get to the dish's control room, hooking up a light speed overdrive from the Master's TARDIS to ensure the signal gets to the CVE in time. Upon transmission of the program, the CVE begins stabilising.

The Master's co-operation with the Doctor has been a ploy, however. Holding the Doctor at gunpoint with his Tissue Compression Eliminator, he transmits a message to the people of the universe, saying that if they do not acknowledge his rule, he will send a signal to close the CVE and restart the collapse. The Doctor climbs onto the radio telescope's gantry to disconnect the power cable, and the Master attempts to prevent him by tilting the dish 90 degrees. The Doctor succeeds in disconnecting the cable, but falls off the gantry. As he hangs on to the disconnected cable, visions of old enemies mock him. Losing his grip, the Doctor plummets to the ground. The Master enters his own TARDIS and it dematerialises.


The Doctor's companions run to the spot where he has fallen. Dying, the Doctor experiences visions of the companions that have accompanied his current form and observes, "It's the end... but the moment has been prepared for." They turn to see the Watcher approach, and as he does so he merges with the Doctor. Nyssa realises that the Watcher was the future Doctor all the time. As the companions look on, the Fourth Doctor regenerates into a new, younger body — the Fifth Doctor.

Cast
Doctor Tom Baker (Fourth Doctor)
Peter Davison (Fifth Doctor)
Companions Matthew Waterhouse (Adric)
Sarah Sutton (Nyssa)
Janet Fielding (Tegan Jovanka)
Guest stars
Anthony Ainley — The Master
Dolore Whiteman — Aunt Vanessa
John Fraser — The Monitor
Tom Georgeson — Detective Inspector
Christopher Hurst — Security Guard
Adrian Gibbs - The Watcher

Production
Writer Christopher H. Bidmead
Director Peter Grimwade
Script editor Christopher H. Bidmead
Producer John Nathan-Turner
Executive producer(s) Barry Letts
Production code 5V
Series Season 18
Length 4 episodes, 25 minutes each
Originally broadcast February 28–March 21, 1981

source: wikipedia

Series 18: The Keeper of Traken

In the TARDIS, the Fourth Doctor and Adric have arrived back in N-Space near the star Metulla Orionsis, home to the Traken Union, famous for its universal harmony. The Doctor describes it as an "Empire held together by people being terribly nice to each other." When Adric tells the Doctor that the TARDIS is headed for Traken, the Doctor is surprised and accuses him of setting the coordinates himself, which he denies. They find themselves in orbit around Traken, when suddenly the figure of an elderly man on a throne appears within the console room. The Doctor correctly identifies him as the Keeper of Traken — one of the few beings in the universe capable of taking control of the TARDIS. The Keeper reveals that he will soon die and have to pass on his powers to a successor, and asks the Doctor to come to Traken, but warns him of great danger.

On the scanner, the Keeper reveals images of Traken, its Fosters — guardians of the spiritual welfare of their capital, and of the arrival of an evil creature known as a Melkur. The creature's baleful influence cannot go beyond the groves and becomes calcified. A young Trakenite woman called Kassia is seen pitying it, bringing it flowers and talking to the statue. The Keeper reveals that the images were from years ago, and that Kassia is now a Consul. He shows images of the day of her marriage to fellow consul Tremas, saying that that day was a turning point for Traken.

Tremas is giving a speech, standing next to him his daughter Nyssa. The party goers gossip about Kassia's attendance at the Melkur statue, saying that people thought she would marry that instead. Tremas and Kassia enter the Keeper's chamber to receive his blessing. The Keeper wonders aloud about the protracted demise of the Melkur, and releases Kassia from the task of tending to it. He says that from then on, Nyssa will look over the Melkur. In the TARDIS console room, the Keeper says that Tremas is his named successor, but that he sensed all pervading evil affecting Tremas, Kassia and Nyssa, and with that disappears.

In the grove, Kassia is tending to Melkur for what is supposed to be the last time. She pours out her heart to the inanimate statue about her concerns, that once Tremas becomes Keeper, he will be taken from her. A voice is heard emanating from Melkur echoing her word "soon". A short time later, Fosters find a body outside the Grove and the Consuls are summoned to a meeting by Kassia. Tremas scans the area, but the readings are off the scale of his instrument. He says that it means some force is taking control of Traken. At the meeting Consul Katura asks if the man has been murdered, and Tremas states that he came into contact with a high energy field. Unheard, Kassia whispers that it is a sign of the power of Melkur. Aloud she says that the great danger necessitates that the Fosters be armed, but the Consuls cannot agree between themselves, and summon Proctor Neman.

The Doctor and Adric look through a Time Log to see if the Doctor has visited Traken before, but discover nothing useful before they arrive. They emerge in the Grove, opposite to the Melkur statue. Adric comments that it looks almost alive. As they exit the Grove, they are surrounded by armed Fosters. The consuls vote to summon the Keeper, just as the Doctor and Adric are brought before them. They reveal to the consuls that they had been invited to Traken by the Keeper. Neman and the other Fosters are sent to check the presence of the Doctor's craft in the grove, but before they arrive, red light is seen shooting from the Melkur's eyes towards the TARDIS, causing it to disappear. Neman returns and says that the Grove is empty. As the Keeper is summoned, Melkur is seen striding from the Grove towards the Court room. The Consuls ask about the identity of the Doctor and Adric, and Melkur stands at the doors of the room seen only by the Keeper, its eyes glowing red. The Doctor asks the Keeper to identify them, but he cries out "evil! the sanctum is invaded! … evil, infinite evil!"

Surrounded by the armed Fosters, the Doctor, arguing for his life, says it was obvious that the Keeper had been attacked. Kassia describes the Doctor and Adric as creatures of evil before becoming overwhelmed and faints. Seeing Tremas's instrument, he says that he could use it to detect the high energy beam used to attack the Keeper. Meanwhile, Melkur is seen attacking Fosters with lasers shooting from its eyes. Examining Tremas's readings, the Doctor says that such plasma fields could not be generated without formidable magnetic containment. Tremas speaks up for the Doctor and Adric to the other Consuls saying no charges have been proved. He invokes Consular privilege to protect them, and Kassia is particularly displeased. Consul Seron says that should they breach any law, Tremas's life will also be forfeit.

Meanwhile Kassia rushes to Melkur. Seeing the Fosters' bodies, she says that this must not be discovered, it is too soon and starts hiding the bodies. The Consuls emerge from the Court room, and hand the Doctor over to Tremas. The Doctor notices that some of the stones in the courtyard have been hit with a plasma beam.

The following day, Nyssa attends the grove to bring flowers to the Melkur statue. As she brushes moss off the statue, Kassia is seen lurking in the bushes. Nyssa leaves and Kassia runs over to the statue and speaks to it. Melkur says to her that when the Keeper dies, he would be the last of his kind on Traken. A short time later, Kassia tells Katura and Consul Luvic that Tremas has secretly been recording the nature of the energy emissions. When Seron enters the room, he scolds them for holding secret meetings, and reveals that Tremas had told him about the recordings, but Kassia says that it holds grave repercussions about the succession to Keeper. The Consuls suggest that Tremas should enter rapport with the Keeper to discover the truth, Seron says that Tremas only did what he did under his suggestion. When Luvic suggests that instead Seron should enter the rapport, Kassia hisses that was not what was intended. Kassia offers to hold vigil over Seron's rapport with the Keeper.

After breakfast, Tremas and the Doctor go to the Grove to search for the TARDIS. Outside the Grove is a crowd of people. Neman says that they are ordinary people who are waiting for a sign from Melkur who they believe to have been redeemed. He says that would not be wise to enter the Grove at that time, but Tremas knows of a secret entrance to the Grove that they can use instead. Meanwhile, Adric and Nyssa are conducting a Fourier analysis of the energy readings. Adric thinks he recognises the energy readings, but wants to check them with the Doctor. In the Grove, Kassia is seen again conversing with Melkur. He gives her a band and asks her to wear it as a token of her allegiance, and she places it around her neck. When the band glows red, Melkur commands her to go forth and be its eyes and ears. Kassia informs it that Seron will enter the rapport instead of Tremas, but Melkur does not seem concerned. The view from within Melkur is seen, that of Kassia shown on two screens with various computer and instrument panels beneath. When Kassia begs it to spare her husband's life, an emaciated hand is seen switching off the two screens, accompanied by a throaty chuckle.

Tremas and the Doctor enter the Court room, and they see a light indicating someone is inside the source chamber. They duck out of sight and Kassia is seen emerging. Tremas goes to speak to her, but the Doctor pulls him back noticing that she appears to be in some sort of trance. When she has gone, they descend into the source chamber, where they see the source manipulator. The Doctor admires it and calls it beautiful. Entering the Grove from the secret entrance, they are observed by the creature within Melkur. The Doctor realises that the TARDIS is in fact present in the Grove, but has been displaced in time. As the Doctor and Tremas go back to retrieve some equipment, the Melkur creature is heard saying "find your TARDIS Time Lord, much good will it do you now…"

Nyssa, seeing the crowd outside the Grove, asks Neman to disperse them but he complains that he cannot legally do so. Nyssa replies that it is the Consuls who determine what is lawful and insists that the Fosters clear the people away, and gives him a purse of money to ensure his compliance. When all is clear, Nyssa and Adric to attempt to enter the Grove, but find its gates locked. Adric picks the lock and slips through the gates. Before Nyssa can enter too, Consuls Katura and Luvic see her and warn her against entering, before leading her away leaving Adric alone in the grove. He is observed by Melkur, and receives a scare when he grabbed from behind, but it is only the Doctor. Retreating to the source chamber, Adric reveals that the energy readings might be from a TARDIS and the Doctor agrees. The Source manipulator activates, and Tremas says the Keeper is being summoned — it is Seron's rapport.

Watched by Kassia, Seron is enveloped in a column of light. The Keeper appears and says that Seron is blameless but doomed. Looking directly at Kassia, he says that they are both betrayed. When the Keeper disappears, Kassia's band and eyes glow bright red, and she shoots laser beams killing Seron. At that moment, Tremas arrives and seeing Seron's body asks Kassia what she has done, but as the other Consuls arrive she declares that Seron was dead because he was rejected by the Keeper. She orders the Fosters to seize Tremas, the Doctor and Adric, but they flee to the grove. As the Doctor attempts to retrieve the TARDIS, Melkur speaks directly to him. The Doctor shields his eyes from Melkur's gaze. The TARDIS reappears, but before they can approach it, Kassia enters and blocks the way. When Tremas goes her, she stuns him with her glowing red eyes. Distracted momentarily, the Doctor, Adric, and Tremas are caught in a net by the Fosters. Kassia approaches Melkur and states that she has done his will, but Melkur retorts that "it is only just beginning…"

Tremas, Adric and the Doctor are placed in a cell in the penal wing by the Fosters. Kassia instructs Neman to watch them, telling him they are the source of evil. She then tells Katura and Luvic that a new successor to the Keeper must be found. The Doctor attempts to pick the cell lock using his sonic screwdriver. In the grove, Melkur informs Kassia that Tremas will continue live as long she continues to obey it, and that she must become the next Keeper. Tremas informs the Doctor that Melkur could not come in contact with the Source, as the bio electronics only permit access to a Trakenite, but they realise that Kassia will fulfil that role.

Kassia meets with Katura and Luvic to persuade them that she should be the Keeper-nominate, which they readily do. Meanwhile, Nyssa attempts to get past Neman to see her father, but when he will not budge, she threatens him with an ion bonder. Neman tries to rush her and she shoots him and another guard with a green energy beam. She proceeds to the cell and frees the Doctor and the others. When Kassia finds the stunned Neman, she furiously orders him to search the sanctum and the Grove. Pursued by guards, the Doctor is forced to stun two of them with the ion bonder. They go to Tremas's quarters, hoping that they have already been searched. The Doctor asks him if he has the master plans for the source manipulator. Tremas is reluctant to allow the Doctor to see them as he swore an oath to keep them secret, but the Doctor impresses the gravity of the situation and he relents. The Doctor devises a plan to trip one of the critical circuits.

The Keeper is dying, and Kassia is summoned by Katura and Luvic. The Doctor and the others try to get to the TARDIS, but are caught in the Grove by Neman and the Fosters. Neman informs them that the Keeper-nominate has sentenced them to death, but a sudden thunder storm terrifies the Fosters and they flee before carrying out the execution.

Kassia enters the Sanctum at the moment of the Keeper's death. She seats herself on the Keeper's throne. In the grove Melkur taunts the Doctor, telling him to look into its eyes for a swift death. Inside Melkur, a hideously deformed figure is seen, and behind him a black wall with roundels is seen. The Melkur statue dematerialises from the grove with a TARDIS-like sound. As Katura and Luvic prepare to use their Consular rings to connect Kassia to the source, the Doctor bursts into the chamber and pleads with Katura not to complete the transition, but she ignores him. Kassia screams in agony, and disappears and the Melkur statue materialises in her place…

The Melkur statue tells the Consuls that the Doctor is known to it. Melkur commands Neman to confine the Consuls to their quarters. As he does so he begins to fade from the throne before disappearing. In the TARDIS, Adric and Nyssa test the drives in case they need to leave in a hurry, but find that they are being blocked. Adric reveals to Nyssa the Doctor's plan to destroy Melkur, but tells her that do so they would also have to destroy the source. The Doctor and Tremas discuss how they might be able to defeat Melkur before he has complete access to the Source. They do not have the five Consular rings, but with the Source manipulator blue-print, the Doctor thinks there may be a way. Melkur dispatches Neman, now adorned with a control band, to secure the blue print document. He enters Tremas's quarters, and asks for the blue print to be handed over. The Melkur statue materialises within the room, and when Tremas refuses to release the document, Melkur shoots energy beams from his eyes at him. The Doctor releases the document, and Melkur burns it with its energy beam, but then fades away again. The Doctor knocks Neman and the Fosters' heads together, and retrieves Tremas's Consular ring.

Nyssa and Adric complete construction of a servo-shutdown, with which they can sabotage the source manipulator. The Doctor goes to the sanctum, and prepares to try to break the encryption of the Source security system, which is based on a single large prime number. Before he can complete the entry of the number, the Melkur statue arrives. The Doctor tells Tremas to remember the numbers 3-3-7. Nyssa and Adric enter the Source manipulator chamber and prepare to attach the device. Tremas tries to make a defiant stand against Melkur, but Melkur mentally controls him. Neman is brought forth and hands his weapon to Tremas. Under Melkur's willpower, Tremas shoots down Neman. Melkur outlines its plans of conquest, saying that many old scores will be settled. It asks if the Doctor still does not know who it is. The Doctor is drawn within the Keeper's inner sanctum, before both he and the Melkur disappear. Inside Melkur, the Doctor immediately recognises the disfigured creature as the Master. The Doctor is paralysed when the Master keys his TARDIS's systems to his bio rhythms. The Master explains that he is nearing the end of his twelfth regeneration, and that with the powers of the Keeper of Traken he can extend his life beyond this final limitation of a Time Lord. Just as he is about to attack the Doctor to take his body, the servo-shutdown begins to destabilise the Source. The Master screams in agony, many of his TARDIS controls explode and a raging fire starts. The Doctor, able to move once again, smashes through a glass panel to escape.

The Doctor appears within the Sanctum and tells Adric to key in the final digits 3-3-7, and he is released. With the encryption broken, Adric's sabotage of the Source is reversed. Luvic runs to the throne to become the new Keeper before the Source dies. Adric and the Doctor return to the TARDIS. As things settle down on Traken, Tremas investigates a mysterious longcase clock. When he touches the clock face, he is transfixed and calls out to Nyssa. The door of the clock opens, and the Master emerges and merges with Tremas… "a new body at last…". Laughing, the newly-regenerated Master enters the clock, which is in fact his TARDIS. The clock dematerialises. Nyssa arrives, and calls out for her father. But there is no answer...

Cast
Doctor Tom Baker (Fourth Doctor)
Companion Matthew Waterhouse (Adric)
Guest stars
Sarah Sutton — Nyssa
Anthony Ainley — Tremas / The Master
Geoffrey Beevers — The Master / Melkur
Denis Carey — The Keeper
Sheila Ruskin — Kassia
John Woodnutt — Seron
Margot Van der Burgh — Katura
Robin Soans — Luvic
Roland Oliver — Neman
Liam Prendergast, Philip Bloomfield, Ralph Morse — Fosters

Production
Writer Johnny Byrne
Director John Black
Script editor Christopher H. Bidmead
Producer John Nathan-Turner
Executive producer(s) Barry Letts
Production code 5T
Series Season 18
Length 4 episodes, 25 minutes each
Originally broadcast January 31–February 21, 1981

source: wikipedia

Series 18: Warriors' Gate

At a null point in space and time on the interface between our universe (n-space) and E-space (exo-space), a slaver cargo vessel becomes trapped. It manoeuvres the timelines using members of the leonine Tharil race as navigators – and they too are the cargo of the grim vessel, held in cryogenic storage in its hold. A Tharil named Biroc flees the craft on the time winds, leaving it moored and trapped, and ventures to the TARDIS, which has also become trapped in a time rift in this strange dimension. The creature manifests itself in the TARDIS console room and imparts to the occupants the warning that he is a shadow of his own past -- and of their future; and that the others that are following him should not be trusted. The Tharil then disappears, with the Doctor in pursuit. Romana, and Adric are left worried about K-9, whose memory wafers have been shredded by the time winds.

The commander of the slave ship, Rorvik, is increasingly angry about their entrapment in the void and the general apathy of his crew toward their condition. When the ship picks up another object in the void, he and two of his crew members use a portable mass detector to track down the TARDIS. Romana steps outside to confront them and is persuaded to return to their ship with them to examine the damaged warp drive of their ship. Rorvik has, however, worked out she may be a time sensitive like the Tharils and is interested in her for potential profit. Adric and K9 both venture separately into the void in her pursuit.

The Doctor has meanwhile reached a vast stone archway in the void, containing an abandoned banqueting hall, decaying skeletons and partially functioning robot knights known as Gundans. They were built by slaves as part of a revolt against a previous tyranny that ended in a massacre at the feast in the same hall. The slavers used the time winds to descend on worlds and enslave the populations. K9 arrives at the Gateway too and begins to help the Doctor repair the Gundan, which has worn itself out. However, before they can obtain any more information Rorvik arrives with some of his crew and seizes control at the point of a gun. Romana has been taken back to the slaver ship for use as a navigator, while Rorvik has used the portable mass detector to isolate the Gateway. He becomes angry when a Gundan comes to life and walks out of the room straight through a solid mirror, and challenges the Doctor to explain the situation. His response is to walk through the mirror: a step the human slavers behind him cannot take.

Back on the slave ship, a Tharil called Lazlo, who had been left for dead by the slavers when his revivification process seemingly failed, frees Romana from certain death in the navigator’s chair. She hides in the hull of the ship and there finds Adric, and together they work out the slave ship is made of the incredibly dense dwarf star alloy, the remnants of a collapsed star. This heavy metal is the only thing that can hold the Tharils trapped in a single timeline. When they meet K9, the badly damaged robot informs them of dimensional instability and the imminent collapse of the void, which is contracting upon itself. The sheer weight of the slave ship is damaging the delicate balance holding the dimension together. Romana is shortly afterward separated from Adric and K9 and reunited with Lazlo, who takes her through the mirrors too.

Beyond the mirror the Doctor has found Biroc, who explains he was able to pass through because his hand was caught in the time winds. They enter an elegant mansion, seemingly frozen in time, where the Tharil explains that his people were the notorious slavers of the Gateway whose rule was overthrown by the use of the Gundans. As the sorry tale of the decay of their society is retold, the Doctor is reunited with Romana but in a bizarre twist they are returned to the reality of the decaying Gateway in the void once the Tharils’ story has been told – and once more find themselves prisoners of Rorvik.

Based on the reports of the shrinking of the Gateway, the Doctor deduces that the slave ship is indeed the cause of the problems and – more worryingly – there is not much time before the Gateway retracts into nothing. Adric has meanwhile hidden himself inside the MZ, a vast portable cannon which the slavers are going to use on the Gateway and the mirrors in an effort to escape the void. When the weapon reaches the Gateway he uses it to free the Doctor and Romana, and the time travellers flee into the void. When the slavers set out in pursuit they find their ship has moved much closer to the gateway – proof positive that the dimension is shrinking and therefore doomed. In frustration Rorvik fires the MZ at the mirrors, but succeeds only in destroying the weapon. The crazed and infuriated slaver now decides to use his ship’s engines to back-blast through the mirrors and escape the void. It is a foolish move: the backblast from the mirrors engulfs and destroys the ship and all its crew.

The Tharil slaves have, however, been freed by Lazlo and Romana, who has formed an empathy with the race. She elects to voyage through the Gateway with them and help the Tharils. The Doctor gives her K9, who will be restored beyond the Gateway, though he can never return. After they depart, the Doctor uses the knowledge he has gained from the Tharils to successfully pilot the TARDIS through the Gateway and back into N-Space.

Cast
Doctor Tom Baker (Fourth Doctor)
Companions John Leeson (K-9 Mk. II)
Lalla Ward (Romana II)
Matthew Waterhouse (Adric)
Guest stars
Clifford Rose — Rorvik
Kenneth Cope — Packard
David Kincaid — Lane
Harry Waters — Royce
Vincent Pickering — Sagan
Freddie Earlle — Aldo
David Weston — Biroc
Jeremy Gittins — Lazlo
Robert Vowles — Gundan

Production
Writer Stephen Gallagher
Director Paul Joyce
Graeme Harper (uncredited)
Script editor Christopher H. Bidmead
Producer John Nathan-Turner
Executive producer(s) Barry Letts
Production code 5S
Series Season 18
Length 4 episodes, 25 minutes each
Originally broadcast January 3–January 24, 1981

source: wikipedia

Series 18: State of Decay

Continuing the Doctor's adventures in E-Space, the Doctor, Romana, K-9, and their newest companion/stowaway, Adric, arrive on a planet experiencing what appears to be a feudal period. The population scratches out a living as subsistence farmers under the thrall of three local lords, Zargo, Camilla, and Aukon, who dwell in a shadowy tower. Adding further fear to their lives, they experience a yearly ritual called "the Selection," in which a sample of young villagers are taken to the tower, never to be seen again. This selection process is enforced by a thuggish band of guards led by Habris.

The Doctor and Romana venture out into the village (not knowing that Adric is following them), and it doesn't take long for the Doctor to realize that something is very wrong when he discovers evidence of technology considerably more advanced than what this medieval society seems capable of producing. With such technology, the Doctor and Romana wonder what happened in the course of the planet's development to cause it to evolve "backward" from a presumably advanced culture to its current rustic condition -- to be in a "state of decay." The arrival and then departure of the Doctor and Romana from the village hall is reported by the headman, Ivo, via an electronic communications device to an unseen figure called Kalmar. As the two head out of the village they are seized by cloaked figures who convey them to a secret base filled with illegal computers and other technology. Kalmar is a scientist - a heretical role in their society - and is very grateful for the Doctor's help in repairing a computer which proceeds to reveal the names of the original chief officers of the spaceship Hydrax. The faces of three senior officers are revealed as those of the Lords of the Tower.

The Lords too have learnt of Romana and the Doctor, and Aukon sends a flock of his winged servants, bats, (aka "The Wasting") to menace them as they travel a clearing near the village.

The Doctor and Romana are now seized by Habris and his guards and taken to an audience in the Tower. Zargo and Camilla entertain them for a while, then are called away to deal with a situation called the Arising. The Doctor and Romana start to snoop around and discover that in fact, the great Tower in which the Lords dwell is itself a spaceship originally from Earth, which also somehow was pulled into E-Space long ago.

Adric has meanwhile wandered into the village and finds himself looked after by Ivo and his wife Marta, both of whom are grieving for their late son who was chosen for the Selection.

In the Hydrax the Doctor and Romana discover rows of corpses drained of blood, while the craft's fuel stores are full of blood. Talk turns to vampires. They head downwards and find an amphitheatre. It is there that the Lord Aukon greets them, welcoming them to his domain.

Aukon invites the Doctor and Romana to become the first of the new servants of the Chosen Ones then tells them that he has Adric much to their surprise. When they refuse they are imprisoned. The Doctor deduces by applying principles of consonant shifting that the current lords' names are a corruption of the original crew names (e.g. "Sharky" becomes "Zargo"). Thus the Doctor realizes that the three lords might not be descendants of the original crew, but members of the original crew themselves. He is reminded of ancient Time Lord stories of the Great Vampires, a giant race of rapacious, destructive, and powerful creatures that were ancient enemies of the Time Lords themselves. He deduces that the Great Vampire escaped destruction at the hands of the Time Lords by somehow retreating into E-Space, and it managed eventually to gather enough power to pull the old Earth ship into this universe and corrupt the crew. Over time, it licked its wounds and gathered power so that it could once again feast on worlds.

Meanwhile, Adric's attempts to mingle with the natives have led to him getting caught up in the Selection. He is put under a hypnotic trance by Aukon and accompanies him to the tower. Normally, the Chosen Ones are chosen for Guards or killed if they defy the Three Who Rule, but Aukon has other plans for Adric when he finds, to his surprise, something different about the third stranger. Aukon plots to change Adric into the new Chosen.

Another rebel named Tarak, makes a solo attack on the Tower in the hope of freeing the Doctor and Romana. The Doctor returns to the TARDIS, while Romana stays with Tarak to search for Adric, whom she knows now is in the Tower's Inner Sanctum. As they try to snap Adric out of his trance, they unknowingly awaken Zargo and Camilla. Tarak is literally throttled by Zargo and dies when his neck snaps on the edge of the "bed". Adric throws a knife at Zargo's heart and Camilla advances on Adric. Romana backs away but Zargo grabs her shoulder. With a toothy evil grin, he chuckles as he pulls the knife out of his heart and is about to give a fatal blow to Romana.

Romana closes her eyes as Zargo draws his arm back for a fatal blow but Aukon orders him to stop. "The boy," he says "is the first of the Chosen Ones, soon to be one of us. He is not for you!" Camilla then asks to have Romana. Aukon grabs Romana's chin and says gloatingly, "The girl is a Timelord, one of the enemies of the Great One. She is to be held for sacrifice at the time of Arising!" Romana and Adric argue about their fate. Adric says if it's a choice between death and joining the dine that means there's no sense in two of them getting the chop. Adric asks Aukon why he is being kept prisoner when Romana is the sacrifice and he is a Chosen One. "I'm sorry Timelady. One of my families died for your lot already. I reckon one's enough!" Romana asks Adric if he knows what happens to vampires when they die. Adric smugly replies "But they don't die, do they Aukon!". They are taken to the bottom of the Tower (as shown in the picture above), where Romana will be sacrificed at the time of Arising and Adric will indeed become a Chosen One.

In the TARDIS the Doctor and K-9 review the old stories about vampires. The lore that the Doctor and K-9 uncovers determines that the Great Vampires could only be defeated by metal bowships driven through their chests (rather like the wooden stakes that work on lesser vampires). He takes the craft to Kalmar's base and there uses scanning equipment to scan the Tower. Under the lake of blood he finds a restless, demonic presence, whom he determines to be the last Great Vampire. He warns it is about to be revived. Kalmar, Ivo and many other villagers agree to help him fight back. This rebel army and K9 make an assault on the Tower itself, killing collaborator guards. Ivo finds Habris and tells him "This is for my son!" and then kills him. The Doctor heads off to the peak of the Tower and, in a burst of characteristic ingenuity, the Doctor manages to rig one of the old scoutships still attached to the spaceship/tower to launch and achieve a trajectory that caused it to point back toward the ground and drive itself into the heart of the subterranean Great Vampire, thus duplicating the effect of the "metal bowships" of Time Lord history.

With the Great Vampire dispatched, the three vampire Lords crumble to dust without the power of their master to sustain them. The Doctor finds Romana and Adric. Together with K9 they leave the planet to its own fate, hoping that, now freed from the corruptive effect of the vampires, it will change direction and develop once again toward its former advanced state and even perhaps surpass it. He leaves the planet in Kalmar's hands, while hoping the next journeys in the TARDIS will take Adric home and lead the craft back out of E-Space.

Cast
Doctor Tom Baker (Fourth Doctor)
Companions John Leeson (K-9 Mk. II)
Lalla Ward (Romana II)
Matthew Waterhouse (Adric)
Guest stars
William Lindsay — Zargo
Rachel Davies — Camilla
Emrys James — Aukon
Clinton Greyn — Ivo
Rhoda Lewis — Marta
Dean Allen — Karl
Thane Bettany — Tarak
Iain Rattray — Habris
Arthur Hewlett — Kalmar
Stacy Davies — Veros
Stuart Fell — Roga
Stuart Blake — Zoldaz

Production
Writer Terrance Dicks
Director Peter Moffatt
Script editor Christopher H. Bidmead
Producer John Nathan-Turner
Executive producer(s) Barry Letts
Production code 5P
Series Season 18
Length 4 episodes, 25 minutes each
Originally broadcast November 22–December 13, 1980

source: wikipedia

Series 18: Full Circle

En route to Gallifrey to return Romana to the High Council of Time Lords, the TARDIS passes through a strange phenomenon and ends up in an alternative universe called E-Space. Neither the Doctor nor Romana herself (who is a little relieved to have avoided home) can calculate why the TARDIS scanner shows the Capitol of their planet when in fact they have arrived in a verdant forest. It later emerges they have journeyed to this pocket universe through a rare space/time phenomenon known as a Charged Vacuum Emboitment.

Nearby is a small but sustainable civilisation of humanoids who live between a river and a grounded but not irreparable spaceship called the Starliner. They came to the planet Alzarius from Terradon and much of the focus of society is on repairing their craft to make it navigable once more. It is an oligarchy ruled by three self-selecting senior colonists knows as Deciders, who ensure the smooth running and order of their adopted world and lay particular store on technical ability. One of the brightest of the younger generation of colonists is Adric, who bears a Badge of Mathematical Excellence in recognition of his computational skills.

However, his brother, Varsh, has rejected the regimented society of the Starliner and leads a band of rebels called Outlers, who steal harvested riverfruit and other foods to survive. However, all is not well in the colony. Strange eggs have started to appear in the riverfruit and this is interpreted by First Decider Draith using the precious System File of the Starliner as an omen of Mistfall, a strange periodic change to the planet during which the natural balance of society is threatened. Soon Mistfall begins, and the colonists move into the Starliner to protect themselves, apparently in a well prepared manner. Adric chooses the moment of confusion to try and steal some riverfruit to prove himself to his brother. Draith gives chase to his young protégé but falls and lands in the river – only to be dragged beneath the waves by a strange force. His last words are aimed at the chief scientists of the colony: “Tell Dexeter we've come full circle!" Adric muses on this as he heads into the forest in panic, finding the TARDIS. The Doctor and Romana take him in and tend to his leg wound, which recovers remarkably quickly. The Doctor heads off to investigate the planet, while Adric attracts Varsh and the other Outlers to the protection of the TARDIS.

The two other Deciders, Garif and Nefred, have meanwhile ordered the Starliner doors closed as per procedure, knowing that both Draith and Keara, an Outler and the daughter of a prominent citizen called Login, have not entered the ship safely. Despite his worries, Login soon accepts a position as Third Decider when it is determined that Draith has died. It is as well the doors have been closed – humanoid, aggressive Marshmen begin to appear from underwater, looking threatening (as shown in the picture above); and soon scuttling Marshspiders hatch from the eggs of the Riverfruit. The Marshmen beat on the walls of the Starliner to gain entry but the fearsome primitive creatures are not admitted. The Doctor, however, gains entry to the Starliner using his sonic screwdriver, followed by a young and inquisitive Marshchild. Both of them are soon found and taken before the Three Deciders. The Doctor is appalled when chief scientist Dexeter starts to perform vivisection experiments on the Marshchild.

A group of Marshmen have meanwhile carried the TARDIS to a settlement cave, intending to use it as a battering ram to force their way into the Starliner. Romana decides to venture outside. She is bitten by one of the Marshspiders and starts to change, seeming possessed. Adric panics and materialises the TARDIS inside the Starliner. When the Outlers emerge Login is reunited with his daughter, but the Doctor is not impressed not to be reunited with Romana. Thus he pilots the TARDIS back to the cave, and finds an alert but amnesiac Romana. The Doctor scoops up the remains of a Marshspider and then reverses his journey once more with Adric and an unconscious Romana in tow. By the time he is back in the Starliner, however, Dexeter has tried to examine the brain of the Marshchild, provoking it to attack and kill him and itself. The Doctor is so incensed he turns on the Deciders and denounces their society – revealing secret ship controls that show the Starliner has been ready to pilot from Alzarius for centuries but, for some reason, the farce of constant repair has been continued. The problem it seems is that though the Deciders understand the technical construction of the ship, no-one knows how to pilot it.

The Doctor persuades the Deciders to give him equipment to examine the cells of the marshspider and marshchild and also deduces that they are from identical DNA sources. This situation is complicated, however, when a transformed Romana releases the emergency exits and allows the Marshmen to invade the Starliner. The colonists retreat before the creatures, many of whom are more inquisitive than dangerous, but anarchy reigns. Nefred is mortally wounded while fleeing one room, but his last admission is that the colonists cannot return to Terradon, because they've never been there. It is realized that the present-day Alzarians are actually a subspecies of the Marshmen, who wiped out the Starliner's original Terradonian crew and then gradually evolved into human form to take their place.

The Doctor uses a protein serum to cure Romana, and they determine from research in the ship's science unit that the ship has been maintained for 40,000 generations by a species that has three aspects; spiders, marshmen, and the current humanoids. They are all from the same DNA and thus have come "full circle". This is the real secret of the System Files.

It is accidentally deduced that oxygen in pure form is problematic to the Marshmen, who have not the capability to cope with the gas in that concentration, and soon this non-lethal defence is used to force the Marshmen out of the Starliner. During their retreat Varsh is killed, leaving Adric in emotional turmoil. With the Marshmen returning to the swamps, the boy stows away on board the TARDIS. His fellow colonists meanwhile follow their dreams and pilot the craft away from Alzarius. The Doctor and Romana are unaware of Adric's presence as they pilot their own craft to another destination.

Cast
Doctor Tom Baker (Fourth Doctor)
Companions John Leeson (K-9 Mk. II)
Lalla Ward (Romana II)
Matthew Waterhouse (Adric)
Guest stars
Leonard Maguire — Draith
James Bree — Nefred
Alan Rowe — Garif
George Baker — Login
Tony Calvin — Dexeter
Richard Willis — Varsh
June Page — Keara
Bernard Padden — Tylos
Andrew Forbes — Omril
Adrian Gibbs — Rysik
Barney Lawrence — Marshman
Norman Bacon — Marschild

Production
Writer Andrew Smith
Director Peter Grimwade
Script editor Christopher H. Bidmead
Producer John Nathan-Turner
Executive producer(s) Barry Letts
Production code 5R
Series Season 18
Length 4 episodes, 25 minutes each
Originally broadcast October 25–November 15, 1980

Series 18: Meglos

The fictional Prion star system contains two habitable planets which have supported civilisations: Zolfa-Thura, a desert world devoid seemingly of life structures bar five giant screens; and Tigella, a jungle world inhabited by the humanoid, white haired Tigellans. The structure of Tigellan society is based on two castes, the scientific Savants, led by the earnest Deedrix, and the religiously fanatical Deons, led by Lexa. The latter worship the Dodecahedron, a mysterious twelve-sided crystal which they see as a gift from the god Ti. The Savants, however, have utilised its power as an energy source for their entire civilisation. The planet’s leader, Zastor, mediates between the two factions, whose tensions have grown greater as the energy source has begun to fluctuate. When Zastor’s old friend the Fourth Doctor gets in touch, the weary leader invites him back to Tigella to investigate and help. When the Doctor, Romana and K-9 try to land the TARDIS on Tigella someone intervenes, trapping them in a time bubble known as a chronic hysteresis, causing them to repeat their words and actions over and over again.

The culprit is Meglos, the last Zolfa-Thuran, a cactus creature who has remained hidden below the surface of his planet in a secret structure. He has summoned a band of ramshackle space pirates called Gaztaks to help him in an audacious plan, and their leaders Grugger and Brotodac are greedy enough to try. Meglos wants to steal the Dodecahedron back from Tigella as it is a Zolfa-Thuran energy source of immense power. To aid him, Meglos uses an Earthling captured for him by the Gaztaks to occupy and take on humanoid form: and the humanoid form he chooses is the Doctor, whom he has trapped in the bubble. While the hysteresis persists Meglos gets the Gaztaks to take him to Tigella, and infiltrates the city in his new identity (as shown in the picture above). Zastor greets “the Doctor” warmly as an old friend, asking him to examine the Dodecahedron, but others are less sure, especially Lexa.

The Doctor and Romana break out of the bubble by throwing it out of phase, and then land the TARDIS on Tigella – but in the middle of the hostile jungle rather than near the city. As the Doctor heads off to find Zastor, Romana stumbles across the dangerous vegetation – deadly bell plants – and then the Gaztaks, waiting patiently for Meglos to return to their spaceship. She gives them the slip after a while and heads off to the city herself.

Meglos has used his time as the Doctor to access and steal the Dodecahedron, shrinking it to minute size. Not all goes smoothly, however, as the Earthling fights back against his occupation, causing green cactus spikes to break out on his skin. When the Tigellans sound the alarm Meglos hides away but the real Doctor arrives at the same time and is accused of theft. His bewilderment and charm are little defence as both Savants and Deons start to panic as the energy levels of the city start to fail. Lexa uses the situation to her own ends. Zastor and Deedrix are arrested in a Deon coup, with other Savants expelled to the hostile surface of the planet, while the Doctor himself is prepared for sacrifice to Ti.

The doors of the city are sealed, with Meglos still trapped inside, with a hostage Savant named Caris for company. She soon gets the upper hand when the Earthling tries another bout of resistance. In a subsequent mix up Romana overpowers Caris, letting Meglos escape and reunite with the Gaztaks, who have staged an attack on the city to rescue him. The Dodechedron is in his possession and the pirates soon blast off back to Zolfa-Thura – though three Gaztaks, half the crew, have been lost.

The real Doctor has by now been able to prove to the Tigellans he did not steal the artefact and there is a doppelgänger at work. Lexa realises her mistake but does not live long to regret it when she is shot dead by a wounded Gaztak who was left behind. The Doctor, Romana, Caris and Deedrix head with K9 for the TARDIS, determined to follow the Gaztak ship.

Grugger’s ship touches down on Zolfa-Thura and Meglos wastes no time in restoring the Dodecahedron to full size and placing it at a spot equidistant between the Screens. He reveals his race perished in a civil war over the control of the crystal, which can power a weapon strong enough to destroy planets. At Grugger’s urging Meglos decides to use the weapon again and to aim it at Tigella.

When the Doctor arrives he plays Meglos at his own game and tries a little impersonation. The situation becomes so confused the Gaztaks lose track of which one is which, enabling the Doctor to change the settings of the super-weapon. Meglos abandons the Earthling, leaving a bemused man watching a cactus creature reassert himself in his laboratory. Meglos knows the Doctor has realigned the weapon. The creature is unable to stop the Doctor fleeing back to the TARDIS, taking the Earthling with him, and is also unable to persuade Grugger not to fire the weapon. From the TARDIS the Doctor and his friends witness the destruction of Zolfa-Thura, the Gaztaks, Meglos and the Dodecahedron.

Caris and Deedrix return to rebuild Tigella, recognising with Zastor and the Deons that old enmities must be put aside and a new society forged. The Doctor and Romana depart and prepare to take the Earthling home, but as they are leaving Romana receives a message from the Time Lords that she must return to Gallifrey…

Cast
Doctor Tom Baker (Fourth Doctor)
Companions John Leeson (K-9 Mk. II)
Lalla Ward (Romana II)
Guest stars
Jacqueline Hill — Lexa
Bill Fraser — General Grugger
Frederick Treves — Lieutenant Brotadac
Crawford Logan — Deedrix
Edward Underdown — Zastor
Colette Gleeson — Caris
Christopher Owen — Earthling
Simon Shaw — Tigellan Guard

Production
Writer John Flanagan and
Andrew McCulloch
Director Terence Dudley
Script editor Christopher H. Bidmead
Producer John Nathan-Turner
Executive producer(s) Barry Letts
Production code 5Q
Series Season 18
Length 4 episodes, 25 minutes each
Originally broadcast September 27–October 18, 1980

Series 18: The Leisure Hive

The Doctor and Romana’s holiday in Brighton is brought to a sudden end when K-9 takes in sea-water and explodes. They instead venture to the Leisure Hive of Argolis, a holiday complex built by the surviving Argolin following their devastating war with the Foamasi. As ever, they arrive at a point of crisis in the year 2290. The Leisure Hive is facing bankruptcy and the Argolin’s Earth agent, Brock, arrives with his lawyer Klout, bearing an offer to buy the planet outright. Regrettably the offer is from the Foamasi, the only species that could live on the radiation-infused surface of Argolis, and so the Argolin Board will not consider it. Hit by the shock of events, the ageing Board Chairman Morix succumbs to a rapid death – the Argolin war curse of advanced cellular degradation – and his consort Mena is declared the new Chairman.

The Doctor is intrigued by the manipulation of the tachyon in the Hive’s Tachyon Regeneration Generator, which is the main tourist attraction and is able to duplicate and manipulate organic matter. He witnesses the Generator kill a human tourist after it has been sabotaged, the latest in a series of acts of wilful damage.

No sooner has Mena returned to Argolis than her own body clock begins to speed up. Earth scientist Hardin has been brought to Argolis to help her and her people by using time experiments to rejuvenate a people rendered sterile by the war of forty years earlier. Recognising the value of scientists, she engages the Doctor and Romana to help Hardin with his work. The time travellers know Hardin has been faking his work, but Romana also feels the experiments should have worked.

The death of Hardin’s assistant, Stimson, is pinned on the Doctor and the Time Lord is forced into the Generator as a trial of sorts. After further sabotage he emerges five hundred years older--an old man with flowing white hair. Pangol, Mena’s son, is the most warlike and vindictive of the Argolin and interprets this as proof of guilt, ordering the Doctor and Romana to be confined. Hardin frees them to help him in his experiments.

Foamasi government agents now make themselves apparent on Argolis — and unmask Brock and Klout as doppelgangers in bodysuits. In truth they are of the West Lodge Foamasi, a criminal faction which made the buyout offer for Argolis and has been sabotaging the Hive to help their negotiations. The agents place them under arrest and prepare to depart.

Pangol now usurps his mother as leader of the Argolin, declaring to Brock and the Board that he is the first of the new Argolin: a product of cloning experiments conducted in the recreation generator. This, he contends, is the future of the Argolin, who will use the Generator to recreate themselves and rise up again. As a skilled tachyon engineer he starts to clone himself in the Generator, creating hundred of Pangols in battle-dress and ready for conflict. The Doctor interferes in the tachyon manipulation with three happy consequences: Pangol’s clones become unstable and disappear, and he is reduced to the age of a baby; Mena is rejuvenated and saved from death; and the Doctor himself loses the added centuries. The only cost is the Randomiser--it had been fitted in the TARDIS to prevent the Black Guardian tracking it--which the Doctor loses in the Generator.

Cast
Doctor Tom Baker (Fourth Doctor)
Companions John Leeson (K-9 Mk. II)
Lalla Ward (Romana II)
Guest stars
Laurence Payne — Morix
Adrienne Corri — Mena
David Haig — Pangol
Martin Fisk — Vargos
Roy Montague — Guide
Nigel Lambert — Hardin
David Allister — Stimson
John Collin — Brock
Ian Talbot — Klout
Andrew Lane — Foamasi
Harriet Reynolds — Tannoy Voice
Clifford Norgate — Generator Voice

Production
Writer David Fisher
Director Lovett Bickford
Script editor Christopher H. Bidmead
Producer John Nathan-Turner
Executive producer(s) Barry Letts
Production code 5N
Series Season 18
Length 4 episodes, 25 minutes each
Originally broadcast August 30–September 20, 1980