Rose asks Sarah Jane -- not to be rude -- who the hell she is. "Sarah Jane Smith. I used to travel with the Doctor." Rose, of course, points out that the Doctor's never mentioned her, and the Doctor nervously tries to cover, saying he must have mentioned her all the time, and Rose is like, "Let me think...thinking...nope. Never." Which of course irritates Sarah Jane, and she takes point. Rose hurries after to see how much she can bug Sarah Jane. Left behind, Mickey looks at the Doctor with a grin: "Ho ho! Mate! The missus and the ex. Welcome to every man's worst nightmare." Mickey, not to be rude, but: Why the fuck do you think you're in this episode (show, season), you half-wit? Every girl's worst, too.
The bizarre quadrille stands outside Finch's office as the Doctor sonics the lock. "Maybe those rats were food," he muses. But for what? Inside the office, there are more weird noises; the Doctor stares at the ceiling. "Rose, you know you used to think all the teachers slept in the school?" The alien bats hang from the ceiling, sleeping nastily. Mickey takes off like a bandit, and Sarah Jane and Rose quickly follow. The Doctor brings up the rear, shutting the door behind him and causing one of the bats to wake, and scream.
The gang comes flying out the front door of the school, Mickey protesting that he will not be returning for any reason. Rose is still freaked that they were teachers. "When Finch arrived, he brought with him seven new teachers, four dinner ladies and a nurse," the Doctor counts. "Thirteen. Thirteen big bat people." And a fat kid in a pear tree. He turns around to go back inside, and Mickey wigs. "I need the TARDIS," explains the Doctor. "I've got to analyze that oil from the kitchen." Sarah Jane grabs his arm and says that she might be able to help him there; she drags him toward the parking lot.
Sarah Jane opens her car truck and reveals a bundle under a blanket. Underneath is a metal robot dog. "K-9!" the Doctor shouts. "Rose Tyler, Mickey Smith, allow me to introduce K-9. Well, K-9 Mark III, to be precise." Rose and Mickey look at each other about how lame this is. "Why does he look so disco?" asks Rose, and the Doctor scoffs with an "Oi": "Listen, in the year 5000, this was cutting-edge!" (Also in the '70s, when he was invented; but there are other cool things from C.E. 5000: one of them is the horrible spaceship next week -- not at all disco -- and the other is Captain Jack -- who transcends disco.) But he's broken. "One day, he just...nothing!" The Doctor stupidly asks why she didn't get him repaired -- while Mickey and Rose continue to wow about the stupidity of K-9 and all he implies -- and Sarah Jane is like, "He's a robot dog from three thousand years hence? Not a Mini Metro?" And she nods to the themes of the season a bit: "Beside, the technology inside him could rewrite human science. I couldn't show him to anyone!" And then he broke. That nothing walks with aimless feet; That not one life shall be destroy'd, Or cast as rubbish to the void...The Doctor coos sweetly at the sleeping dog: "Oh, what's the nasty lady done to you?" Rose rolls her eyes and Mickey stares as the Doctor makes sweet, sweet love to the metal dog. Sarah Jane shoots Rose this look like, "And you bring him, what, a Top Shop hoodie and a cell phone? Bang. I got a dog that can talk and shoot lasers, bitch." If Mickey weren't here getting just as strongly shit on, this would hurt you in the feminism, but rivalry in this show doesn't follow gender or age lines: it's omnipresent and equilateral, just like in real life. Rose and Sarah Jane aren't like this because they're simpering women, or because they're bitches: they're like this because they're human beings, and have touched magic and passed it on, and because everything ends. Alien eyes watch as Rose realizes she's now up against not one but two favorite Companions: "Look, no offense? But could you two just stop petting for a minute? Never mind the tin dog, we're busy!" The Doctor closes the trunk, grinning hugely; the bat flies across the moon, screeching.