The Doctor loves this impulse too: "And you came," he grins madly. Ida wonders how they could not, because she is good; Zach switches off the hologram. The Doctor looks around at them all, so fondly. "So, when it comes right down to it, why did you come here?...Because it was there. Brilliant." He approaches Zach slowly, carefully, hollering his intentions as he closes in, and embraces him. Zach loves it, Ida thinks he's nuts, everybody stares. "Human beings!" cries the Doctor. "You are amazing!" Rose chuckles; the Doctor thanks Zach for letting him hug him, and Zach just shakes his head: "Not at all." But apart from that, the Doctor clarifies, they're all completely mad. Toby stares, marveling at the mood swing. "You should pack your bags and get back in that ship and fly for your lives," says the Doctor. Ida's like, "And you got here how?" The Doctor stumbles around, not talking about the TARDIS -- "hard to explain...it just sort of appears" -- and Rose offers to show her: "We parked down the corridor from um...oh, what's it called? Uh, habitation area..." The Doctor remembers: "Three." Zach looks up suddenly: "D'you mean Storage 6?" The Doctor is cheerful as Zach looks at Ida uncomfortably; he figures it out as he's speaking: "It was a bit of a cupboard, yeah. Storage 6, but you said...You said Storage 5 to 8."
The Doctor goes running, Rose running along behind most Excellently, but he won't answer her, and she's only smart when he's not around. They get to the last door before Storage 6, and it's out of commission. He looks out a small porthole. First out, then down, Rose crying out, "What's wrong? What is it? Doctor, the TARDIS is in there. What's happened?" The Doctor stares out, into impossible space, horrified. Sick: "The TARDIS is gone." He backs away, feverish, stuck in a nightmare. Rose puts it together, but still doesn't believe it: "But it's gotta be out there somewhere." She peers out at the rocks and ruin, and the Doctor has to remind her to look down. Into the Pit.
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.