Amy does for her job what the Doctor did to her. She shows up, she promises the world -- and more importantly intimacy -- and then disappears forever. It's like Donna being a temp, but incredibly personal. The Doctor failed her, and she had nobody else. She's a hard shell around a groovy angry center, and as any of the ecdysiasts of my acquaintance can tell you, the best revenge is being hot and then leaving at the end of your shift. It's power, and a damn sight more valuable feminism than complaining about Uma's Photoshopped thighs. The only people who pay in that scenario are the men, and complaining about sex work in this way is an incredibly sheltered attempt at making grown women's choices for them, which is gross.
And even if she were a stripper, that would still be awesome, because the show has to accomplish a lot in making her character work, and telling us straight up that she prefers to be vacant from her life -- from Rory, from the thing at the end of this episode -- while simultaneously taking a ferocious bite out of it, because of who she is, is accomplished quite easily here. If your knee stops jerking for a second, you'll see how: Amy professes, and fails, at the same relationship -- with Earth, and humanity -- that the Doctor professes and fails to have with same.
The secret door pops open, and a stocky unshaven bloke with a big black dog comes out. The dog is growling, Amy thinks at first, but soon realizes they're both growling and barking: One creature, taking the form of two creatures. (Brilliant. I love this bit. Could have been its own episode, but no.) "Clever old Multiform," the Doctor chuckles, and makes fun of him screwing up the voice. "Where did you get the pattern from? You'd need a psychic link, a live feed. How did you fix that?" Coma patients, clearly.
The snarls echo all over the place, and the Doctor tells him to "stay," and there's a bunch of back and forth about how they have backup coming, but they don't really -- "That was a clever lie to save our lives," he hisses -- so then he changes tack and says there's no backup, which is now why they're safe, because they're not a threat. Whenever anything happens, Amy goes, "What?" It's sort of funny, but this episode is catchphrase central so it's also sort of obnoxious and coked-up first-drafty. This goes on a while, and then the voice from the crack echoes through the sky: "Attention, Prisoner Zero. The human residence is surrounded..." Backup. The Doctor explains that they do have backup after all, and that's why they're safe. "Prisoner Zero will vacate the human residence or the human residence will be incinerated."