The Doctor returns two years (again, five minutes) later, and Amy decides to go with him, as long as she can get back in the morning. They go to Starship UK, a ship travelling the sky after some sort of apocalypse falls on earth. People are disappearing below, and there seems to be some sort of beast. Amy, while investigating a tented pair of tentacles, gets taken to a room. There she is shown a video that tells her she will discover the truth about Starship UK, then will be given the choice to either remember it, or to forget it. Amy watches the video, and presses the "Forget" button, as indeed does everyone else on the ship who has seen the video. The Doctor and Amy decide to go down into the belly of the beast--or, rather, the mouth. The Doctor and Amy escape by making the creature vomit. Then they meet the Queen of England. She, too, wants to know what's going on. They're led to a control room. They discover that the thing leading the ship is a star whale. And it's being tortured into keeping going. The Queen has repeatedly hit the Forget button over the course of her reign. It comes down to a choice between freeing the star whale and killing the entire UK and letting the star whale be tortured, which causes major conflict in the Doctor. Eventually Amy must make the choice for him, but what does she choose?
I liked this episode. I liked how smart Amy was. Her decision and like quick-thinking and good analysis of the situation was brilliant. It's not my favorite episode, but I enjoyed it.