This episode continues from the cliff-hanger at the end of previous one. The Doctor and gang make their way into the ship with the angels in pursuit.
While they make their escape the Doctor notices Amy "counting down" from ten, although she remains unaware of it. He discovers that an angel has got inside her and will take over when she gets to zero. The only way to stop it is for her to close her eyes. But the only way to stop and angel is to look at it...
Also the crack in Amy's bedroom wall in episode 1 makes another appearance. It appears to be following her...
There are some creepy moments in the episode such as Amy's countdown and the soldier forgetting that his comrades ever existed after they go to investigate the crack.
Also we discover that River Song was in prison for killing a "good man". Methinks the next time the Doctor and River meet will explain who that was.
This was not a bad episode by any measure, but it did feel like it was just a smaller part of the "season arc" rather than a stand-alone episode.
