Teen Wolf: Season 3, Episode 15

3 - 15: Galvanize

William Barrow, an electrical engineer turned mass murderer, escapes during a surgery at the hospital and hides out in the school. He abducts Kira, takes her to a power plant and attempts to electrocute her, but she inexplicably deflects the electricity, killing Barrow and shutting down the power for the entire town. Just after the blackout, five hooded figures attack Isaac.