[And then everything is suddenly shaking around you as everything just starts shifting.]
[The tent suddenly become bigger, stone melting away into wall plaster and weird little...bulby things as the tent fabric fuses with remnants of a patient's room in a hospital, but most of the structure taking on the form of the main room in the TARDIS. The big box suddenly becomes a lot smaller, appearing near the door of the room instead.]
[There's more gadgets, there's more future things, there's a console full of buttons, and the faintest smell of sheep wool.]
[The Doctor is suddenly on his feet, looking full of energy.] Yes, that's right! Big box can't open because the big box is protecting Amy. For...some reason. That's still a blank, but it's bad to let her out too soon.