This episode title is kind of a misnomer… It’s not actually about the Doctor’s wife. Eventually we’ll meet her, don’t you worry!
Okay, so we start off getting a message from a time lord, a box wrapped in psychic paper.
The Doctor then follows it to another universe where we meet a bunch of “scavengers” who live on this living asteroid, then the TARDIS breaks. The Doctor hears all these time lords and so thinks there’s a bunch of them around somewhere. Oh, and we also meet Idris, who’s acting kind of funny. “Goodbye! No, what’s the other one? Hello!” And she bites the Doctor, but the servant Ood locks her up. The Doctor heads off to find the time lords and tells Amy and Rory to go back to the (broken) TARDIS.
Meanwhile, the Doctor figures out that these time lords he’s hearing are just distress signals (like the box at the beginning), since the “family” that lives on this asteroid are not only scavengers of things, but scavengers of body parts and have chopped up some time lords along the way. The living asteroid named House learns from the Doctor that there are no more time lords or TARDIS coming, so it takes on the Doc’s TARDIS, with Amy and Rory inside. Oh and we find out that Idris was acting weird before because she took the soul of the TARDIS. That’s right, when the Doctor is talking to Idris, he’s actually talking to the TARDIS itself! She even makes the sound!
Good time for him to learn some things about “Sexy” (that’s what he calls the TARDIS on occasion) while he can. They talk about when he “borrowed” the TARDIS from a time lord museum, and she says the door was unlocked because she unlocked it. The TARDIS wanted to go see the universe as much as the Doctor and made it happen by letting the Doctor steal her. And we learn about why the TARDIS seems to end up in random locations
some most of the time: the TARDIS doesn’t always take him where he wants to go, but where he needs to go. Anyway, during all of this, they also figure out that House, the asteroid that has taken over the TARDIS, has taken other TARDISes (TARDISi?) before but Idris and the Doc won’t let this happen, so they decide to build a makeshift TARDIS to go after theirs. It’s actually pretty impressive.
In the meantime, Amy and Rory are trying to draw out the destruction of the TARDIS by having the asteroid chase them around and play with their minds. At one point, it separates them and makes an old Rory yell at Amy for leaving him again for 2000 years, then an old Amy accuses Rory of leaving her. Why couldn’t they have just gotten lost in the pool? Then Idris makes a psychic connection with “the pretty one” Rory (obviously her and the Doctor disagree on that…) and gives him directions to the cached control room to fix things. Always a good idea to back things up, I guess? And they have to use their minds to get in, it’s pretty bizarre.
Anyway, thanks to Amy’s quick thinking, they get inside and lower the shields so the makeshift TARDIS can get in and Idris transfers the matrix back into the TARDIS. But before she dies, she tells the Doctor something – “the only water in the forest is the river.” Nonsense now, but it’ll be useful later… Anyway, Amy and Rory go find their new room – no more bunkbeds – and the TARDIS sends them off once more.