Doctor O: Rory and Amy, they may not trust both of us.
Doctor G: Are you thinking what I'm thinking?
Doctor O: Inevitably.
Doctor G: Heh. I'm glad we're on the same -
Doctor O: - wavelength! See? Great minds!
Doctor G: Exactly! So, what's the plan?
Doctor O: Save them all, humans and gangers.
Doctor G: Tall order! Sounds wonderful.
Doctor O: Is that what you were thinking?
Doctor G: Yes! It's just so inspiring to hear me say it.
Doctor O: I know!
The whole thing happens with lots of ecstatic grinning and happy eyes and by the end, I kind of expected to see them fall into a gleeful cuddle like a pair of Labradoodle puppies. Alas, there are more important matters to attend to, so they head off in perfectly synchronized unison to join the others at the door. "Hello! Sorry," they say at the same time. Amy regards them both with a frown and notices that one of them is wearing the Doctor's usual black shoes and the other is wearing the borrowed brown shoes. They talk all over each other about nothing in particular and then suddenly shout "Breathe!" to Amy at the same time. Amy stares at them in confusion, which seems natural. "We have to get you outside, and the gangers, too," one of them says. "They are trying to kill us," Cleaves reminds them. "They're scared," he reminds her right back. The Doctors talk themselves into realizing there's an escape route. "Yowza!" says a Doctor, pulling back some paneling to reveal a grate. "You know, I'm starting to get a sense of just how impressive it is to hang out with me." The other Doctor questions their use of the word "yowza" but, again, they have more important matters to deal with.
By the time the gangers break through, the originals have escaped through the grate. Ganger Cleaves follows the whirring of the sonic screwdriver and finds the Doctor and her other self-sealing the grate shut. She sighs in frustration.
In a corridor somewhere in the monastery, ganger Jen is oozing blobs of yogurt from her fingertip and poking at the stone wall. "Stop," she whispers again and again. She squeezes her eyes shut and takes a second to compose herself. She opens her eyes with renewed purpose and marches off somewhere. Rory peers around a corner after she passes by, then follows quietly.
The Doctors and the others wander through the monastery. They need to contact the mainland, Cleaves and Jimmy say, so the army will send a rescue team. Amy reminds them about Jen and Rory. A Doctor wonders if there's a computerized map somewhere they could use to help find them. Cleaves said they'll need to get to power back on before they can use the scanner. Amy coughs. The corridor they're walking through is hazy and there's a hiss of acid coming from the broken pipes. The others start coughing, too. "Acid interacting with the stone," a Doctor says, "creating an asphyxiant miasma!" Or, as he clarifies for the confused, "Chokey gas!" Everyone is struggling to breathe. They head for the "evac tower" to try to get above the gas.