The Jonathan M. Woodward Memorial Award for this new series of the show goes to William Thomas, who appeared in the Seventh Doctor story "Remembrance of the Daleks," and so is the first actor to make the jump. Here, he plays a Mr. Cleaver, the assistant to the new Mayor of Cardiff. We open on him speaking with her, stashed ominously out of frame, discussing a Broken As Designed nuclear power station set for the heart of Cardiff. Cleaver begs her to stop construction, fearing that the project could result "in the death of millions." And the Mayor plays ignorant, promising him that, as an expert, she'll go along with his wishes. It's MI-5 Margaret, the female (and coolest) of the Slitheen family. Well done, Margaret. Her stomach rumbles, in case you've forgotten her face, or the Slitheen's unfortunate gas issues. "But you promise you'll stop it, today?" Cleaver begs, and she snaps that it's a matter of course: "Nothing is more important than human life!" Something about her tone, the hardness in her face, throws Cleaver off, and she giggles it away. Margaret confirms that nobody else has seen his results. He wipes his brow with relief, his back turned to Margaret, and he replies that no one else knows. "The scale of it," he says, as she reaches up to unzip her forehead, "...destruction like the British Isles has never seen before." He worries that the project is really just intended to do exactly that: wipe Cardiff off the map. He praises the Mayor, and Margaret, who is now in full Slitheen form, attacks.

Episode by Russell T. Davies. Here's a frightening proposition for you: this slot was originally offered to Paul Abbott (Shameless), and his pitch was a story ("The Void") revealing that the Doctor had actually bred Rose to be the perfect Companion. Abbott had other duties, the world kept turning, we got MI-5 Margaret instead. Well done again.

Mickey's train from London pulls up at Cardiff Central, and he takes off for the TARDIS, which is parked in the middle of the Millennium Centre square. The door opens immediately at his knock, and Captain Jack sticks his head out: "Who the hell are you?" (Drink!) Mickey tells him off, and Jack tells him to get lost, but Mickey pushes his way in. Hmm. Jack shuts the door, guessing that he's just met Mickey. Charming, both of them.

Inside, the Doctor's doing some kind of random TARDIS maintenance with a blinking light strapped to his head, which looks ridiculous.