Attack on Titan: Season 1, Episode 20

1 - 20: Erwin Smith - The 57th Exterior Scouting Mission (4)

The Female Titan has been captured, and it's Erwin's goal to find out who the human is lurking inside it. Meanwhile, the Scouts realize that the reason Levi told no one about their true mission outside the wall is because there is a spy among their ranks.