Back in the control room, the Doctor is on Zach: "The ground gave way. My TARDIS must've fallen down right into the heart of the planet. But you've got robot drills heading the same way..." Zach assures the Doctor they can't divert the drilling, but the Doctor follows him, a new sort of man, the kind of guy who begs: "But I need my ship. It's all I've got. Literally the only thing." She's the last part of Gallifrey, the last TARDIS that will ever live or sing. The only angel that won't age or die on him; the thing that connects you to everything in all of space and time. The Age Of Steel was one way to lose the universe; this is another. She's the other half of the Doctor and she is gone. Into the Pit. "Doctor," hisses the now-irritated Zach, "we've only got the resources to dig one central shaft down to the power source, and that's it. No diversions, no distractions. No exceptions. Your machine is lost. All I can do is offer you a lift if we ever get to leave this place, and that...is the end of it." Zach leaves, and Ida approaches softly, kindly. The Doctor is completely lost. Tennant's version of the Lonely Little Boy was never quite as heartbreaking as Eccleston's. Until just now. Ida offers sweetly to put them on the duty roster for the Sanctuary Base -- "We need someone in the laundry" -- and follows Zach out. The Doctor and Rose look at each other blankly; the last person in the room, an Ood, exits, leaving them alone. The Doctor goes to Rose, settles down beside her, and goes very quiet and very still. "I've trapped you here," he says, horrified. She smiles at him: "Don't worry about me." The smile goes underground, but it's still there: "Okay, we're on a planet that shouldn't exist, under a black hole...and no way out. Yeah, I've changed my mind: start worrying about me." She laughs nervously, and the Doctor pulls her to him, hugging her tight, and staring up, up, up.