Then, too soon, it's Steffi's turn, cut off from the others by a sudden wall of water, Adelaide screaming that they'll find a way back to her, somehow, they'll find a way to save her. The Doctor makes his way across the red sands in his spacesuit, still listening as they shout, as Steffi locks herself in a small glass cabinet off the main bridge room, and turns on her last message from home, the little German girls telling her jokes, and the crew can't get to her, and she's weeping, holding onto the screen as if she's hanging from it, and then she dies.
Adelaide reroutes the rest of them through another corridor as Ed checks the shuttle systems and gets ready to fly, above it all. Just as he's finishing up, as Adelaide's shouting at Roman to pull it together and stop staring as another colleague drops in the corridor behind them, and they keep running. And down at the bottom end of the shuttle, just as Ed's closing the hatch, Maggie appears -- smiling and staring -- and shoots water up at him. And Ed's last goodbye is this, as he logs a self-destruct, as his pupils go white: "Hated it, Adelaide. This bloody job. You never gave me a chance. You never could forgive me. See you later." He blows the shuttle, and everybody is thrown around, and out on the sands the Doctor falls to his knees. He looks back, in terror and anguish. Air and fire explode into the vacuum; he can hear them on the radio as they lose oxygen, as everything burns. And he climbs, above and away from it all.
"I'm not just a Time Lord, I'm the Last of the Time Lords," he said. "They'll never come back," he said, in equal resentment and loneliness, "Not now." The Doctor stands in flame, watching Bowie One burn. "I've got a TARDIS," he said. "Same old life... Last of the Time Lords... And they died, took it all with them. The walls of reality closed, the worlds were sealed, gone forever... The Time Lords kept their eye on everything. It's gone now... But they died, the Time Lords! All of them, they died. I'm the last of the Time Lords..."
It's one thing he always had in common with every Companion: That loneliness. That unique feeling of being singly gifted and singly afflicted. The last -- or the first -- of something. He's been the last of the Time Lords for so long -- two and a half lives, and counting -- that he hasn't even questioned whether taking all their burdens on his back, shepherding the fixed points, the duty of Rassilon and the screams of dying Pompeii, is worth doing. But the thing about Adelaide, and about her granddaughter Susie, is the way they cross the line from the other side: Confronted with death and enormity, they take their place in the story. You can't hold a six-year-old girl, who has just lost her hero -- like he wants to -- and say "Imagine all the wonderful things about this death."