The Doctor's unsurprised to hear that he has not: His sofa is not the sofa of a traveler, and Craig's resemblance to his sofa is growing as well. As Craig speaks about how he'd miss Essex, he fondles Sophie's keys; finally the Doctor asks him why. It's cute.
"You're weird and you can cook, it's good enough for me." The Doctor is overjoyed to have his own "keys" that belong to a "door" that means he has his own gaff: "Yes! Me with a key." Craig mentions, sort of out of the side of his mouth, that he and Mark had an agreement about getting scarce if things required it, which of course the Doctor completely doesn't get what he means. "In case you want to bring someone round? A girlfriend, or a boyfriend?" The Doctor is like, "You bet your ass I'll shout if I end up bringing somebody home. Probably, like, I WAS NOT EXPECTING THIS!"
It's like the sun coming out, it really is. Tighter writing, funnier gags... It's like a completely different show. Whoever wrote this, hold onto him. The Doctor tells Craig not to touch the rot, ever, and then takes his bluetooth elsewhere, to talk to Amy. So he's set that up at least. How much hopping about is there going to be? This could be delightfully complicated or delightfully simple.
Sophie, between the weirdness and the huge amounts of cash lying around, assumes that "the Doctor" is a drug dealer. Craig is only surprised by that because, as any good guest star on this show knows, once you trust the Doctor you don't go back. Outside, somebody else gets taken by the upstairs... Which the Doctor and Amy have figured out is the reason the TARDIS can't land: She can't quite become real, locked in a "materialization loop." Amy's like, "So go upstairs and sort it!" But it's not that obnoxious. I don't know how long all of this is taking -- the house keeps napping people and they keep yelling at each other over the earpiece as though it's one long conversation, but who knows. If Amy's really popping around up there they could be having this conversation upside down and backwards, right? Like "Blink," but as a neverending phone call.
Outside the room, Craig can only hear gibberish, thanks to the bluetooth, which is the only tech the Doctor can even use, including the sonic. So in addition to living in this random flat, he also has to be common people in other ways, like not having magic things all the time. "Arbuckle rare tarantula on the table," says the Doctor. "Practical eruption in chicken! Descartes Lombardy spiral!"