Zach calls over the PA for all "non-essential Oods" to be confined. On the exploration deck, Ida and the crew are preparing to go down the shaft. The Doctor is already wearing a spacesuit when he walks up. Ha! Zach stares at him: "Reporting as a volunteer for the expeditionary force," says the Doctor, and Zach shakes his head: "Doctor, this is breaking every single protocol. We don't even know who you are." But the Doctor points out that Zach trusts him -- they all trust him. And they do. "And you can't let Ida go down there on her own!" adds the Doctor. "I should be going down," protests Zach, but the Doctor shakes his head: "The Captain doesn't lead the mission. He stays here. In charge." Zach is bitter, helpless, overwhelmed: "Not much good at it, am I?" The Doctor just looks at him. As Zach calls out the final prep, walking away, Rose approaches the Doctor. They stand facing one another; the Doctor checks his vitals and laughs that he hasn't worn a spacesuit in ages. She demands of him a promise that he'll bring it back in one piece. He salutes -- "Yes sir!" -- and puts on his helmet. "It's funny," she says. "Because people back home think that space travel's gonna be all whizzing about and teleports and anti-gravity...But it's not, is it?" Her voice breaks slightly: "It's tough." The truth inside the wish. "I'll see you later," the Doctor says confidently, and she grins: "Not if I see you first." She pulls his head down, laughing, afraid, and plants a kiss on his helmet. It's sweet, and nice, and touching. But it's also goodbye, and they don't know that, but it's true. On the other side of Hell, we burn off what doesn't work; that doesn't mean you only have to do it once. Rose won't be seeing the Doctor again. Not like this.
Danny addresses the Ood in their pens: "You will remain here. No command can override this. Have you got that? My instructions only." Zach counts down the explorer capsule over the PA; the Doctor and wonderful Ida get inside. Jefferson closes the door after them, synonymous with safety and protection, a one-eyed hero who will always hold the line. He salutes them, and Rose waves. The Doctor and Rose smile at each other, and the Captain gives the final order: "Release."