Fallen - Season 1 Episode 3 Butterfly

Cassie, the only person to escape Sword and Cross, is confronted by a nightmarish creature. Luce suspects that Howson is controlling their memories-she steals photographs of her and other residents undergoing a medical procedure that they don't remember having. The residents are sent on a hike while Howson orders Cassie be brought to Sword and Cross. Daniel and Luce grow closer trying to work out their hidden past. When something attacks Luce in the lake, Luce and Daniel are taken to the medical bay-they break into a restricted room and are shocked by what they find.