Series 1 Episodes: Boomtown

The Doctor has landed the TARDIS over the Cardiff Rift, located in the Roald Dahl Plass leading to the Wales Millennium Centre, left open after the Gelth were defeated in 1869, and using the slow radiation leakage to recharge the TARDIS. As the process will take a whole day, he, Rose, and Jack are joined by Mickey in Cardiff and take the opportunity to explore the area. While they enjoy a meal at a restaurant, the Doctor notices, to his dismay, the front page of The Western Mail, with the headline "New Mayor, New Cardiff" and a picture of Margaret Blaine, a Slitheen in its human form whom they previously encountered. Since their meeting, Blaine has become the Lord Mayor of Cardiff, and initiated the construction of a nuclear power plant. However, several people had found significant flaws with the design that could lead to a nuclear meltdown, and had approached her about these issues, but they have since disappeared, Blaine having killed them herself. During a recent press conference, a young reporter approached Blaine about these deaths and the information they had left behind. Blaine invited the reporter to follow her into the restroom where Blaine plans to kill her, but had a change of heart as the reporter talks about her family, realizing that she herself no longer has one.

Realizing that they must stop Blaine, the Doctor's group converges on City Hall and eventually capture Blaine after chasing her through repeated uses of a teleporter. She tells the group that the teleporter is how she escaped the destruction of the rest of her family, and that she hopes that, as planned, the meltdown of the plant would open the Rift and destroy the planet, herself using a hidden tribophysical waveform macro-kinetic extrapolator — a pan-dimensional surfboard — to escape the explosion. Rose notices that the name of the plant, Blaidd Drwg, is Welsh for "Bad Wolf", a phrase that she has observed before in her adventures with the Doctor. The Doctor tells Blaine he will take her back to her home planet of Raxacoricofallapatorius, but Blaine notes that the Slitheen family are convicted criminals there and she will be executed, which the Doctor insists is not his problem.

Jack recognizes that the extrapolator can be used to halve the time to refuel the TARDIS, and stays there to install it. Rose and Mickey go out for a drink to discuss their relationship; Mickey admits to seeing someone else since Rose is not there for him, which angers Rose. At the request of Blaine, the Doctor joins her for one last meal at her favourite restaurant, equipped with bracelets that will electrocute Blaine if she gets more than ten feet away from the Doctor. Blaine attempts to kill the Doctor through various means, but the Doctor is able to casually block the attempts. Blaine then attempts to gain the Doctor's sympathy, explaining how she will be executed and if he could take her to a different planet instead. However, before the Doctor can agree, a large earthquake shakes the area.

The group reassembles in the TARDIS, where a bright column of light is shooting up overhead. Jack tells the Doctor that it is the power from the Rift, brought upon by the extrapolator. The Doctor realizes that this was Blaine's plan all along - the extrapolator would have been found by someone of advanced technology to recognize the Slitheen, and would have activated it, causing it to lock onto the nearest alien power source (the TARDIS in this case), as to tear open the Rift and eventually the Earth, while she would have still ridden the device to escape the destruction. Blaine takes Rose hostage and demands the extrapolator, but before she can use it, the heart of TARDIS opens and shines in her face; the light overtakes her, and shortly her skin suit falls empty to the console floor. The Doctor and Jack manage to close the TARDIS console and reseal the Rift once more. When they investigate the suit, they find a Slitheen egg; the Doctor surmises as the TARDIS is telepathic, it may have sensed that Blaine wanted a second chance and gave that to her. As the Doctor, Rose, and Jack prepare to travel to Raxacoricofallapatorius to deliver the egg, Rose realizes that Mickey has left; the Doctor offers to wait for him, but Rose lets him go, allowing him to also have a second chance.

Doctor Christopher Eccleston (Ninth Doctor)
Companions Billie Piper (Rose Tyler)
John Barrowman (Jack Harkness)
Writer Russell T Davies
Director Joe Ahearne
Script editor Elwen Rowlands
Producer Phil Collinson
Executive producer(s) Russell T. Davies
Julie Gardner
Mal Young
Production code 1.11
Series Series 1
Length 1 episode, 45 mins
Originally broadcast June 4, 2005