With graduation approaching, a supernatural force rides into Beacon Hills and crosses paths with Scott and his friends, while Liam discovers evidence of a new enemy in the high school.
With the identity of the Beast finally revealed, Scott and his friends are in a race against time to stop the Dread Doctors from implementing their final plan.
Hoping to align with a familiar ally, the Argents reveal a key clue to the mystery of the Beast of Gevaudan. Meanwhile, Scott tries to take on the Beast himself.
After discovering Lydia is in imminent danger, Stiles creates a desperate plan to break her out of Eichen House. Unbeknownst to Scott and his pack, however, Theo has his own plans for Lydia.
When Scott McCall is convinced by his best friend, Stiles, to join a search in the woods for a missing body, something comes out of the darkness to take a bite out of his side.