For what seems like the eighteenth time, they tear down the barricades they just built, moving from what they've defined, in fear, as their world, in order to move beyond, because that's the only option, into another world entirely. Which in this case is obviously the observatory. Once more, Rose is transfixed by the Wolf; this time she's saved by Lady Isobel, who tosses a pan of mistletoe brew onto the Wolf, who runs off. The Doctor tells her that it was a good shot, and she explains that she figured out the mistletoe; Sir Robert kisses his wife and sends her back downstairs again. They order each other to stay safe, and Lady Isobel disappears again. Sir Robert stares after her, sad and afraid.
In the observatory, the Doctor notes that there's no mistletoe in the walls: "Your father wanted the Wolf to get inside!" Sir Robert faces off with the Doctor as he worries and mumbles about defending the room: "Just do your work and I'll defend it....Now get inside." "Never morning wore To evening, but some heart did break." Everybody stares, but they get inside, and Sir Robert closes the door with them inside. The Doctor asks for the diamond, and the Queen asks for what purpose. "The purpose it was designed for." Earth is defended.
Outside, Sir Robert listens to the howls of the Wolf, and grabs a sword from the wall of Torchwood.
The Doctor calls Rose over to the telescope mechanism, and for the second time this season tells her to shift a lever; turn a wheel, get the mechanism working. He's relying on her; he's forgetting that he's not human. Rose glances askance at him: "Is this the right time for stargazing?" And the Doctor says it is: in Torchwood House, it's always time for stargazing. "A time to sicken and to swoon, when Science reaches forth her arms to feel from world to world, and charms her secret from the latest moon."
Outside the observatory, the Wolf comes upon Sir Robert guarding the door, and he looks at him, disgusted: "I committed treason for you. And now my wife will remember me with honor!" He manages one slash with his borrowed blade, before he is devoured. There is no delight in this.
Rose listens to Sir Robert screaming, inside the observatory. Queen Victoria holds up her crucifix, calling on her world to save them all. The Wolf beats at the door, and the gears go on grinding as Queen Victoria prays. Rose is confused: "You said this thing doesn't work!" It doesn't work, as a telescope, because that's not what it is: "It's a light chamber! It magnifies the light rays like a weapon. We've just got to power it up!" They keep working and Rose works it out, Wolf to Wolf: "Moonlight! But it needs moonlight! It's made by moonlight!" The Doctor, remembering that she doesn't remember: "You're seventy percent water, but you can still drown. Come on!" You're one hundred percent grace, but if you forget that fact, or the other hundred percent of you that's made of dirt and earth, you get hollowed out. They work and work, and finally the moonlight bounces from prism to prism, reflected, beautiful. The Wolf breaks through the door at that moment, of course, and is not caught by the beam of light, which shoots low onto the floor. The Wolf jumps upon the Queen just as the Doctor dives across the floor, throwing the Koh-I-Noor into the beam.