When an old friend returns to Beacon Hills with a problem he can't solve, Stiles's brains and Lydia's banshee powers are put to use. Only they can accomplish what must be done to save their friend. As things gets heated, Stiles experiences some rough patches with his ex-girlfriend Malia and the love of his life: Lydia. Stiles's and Lydia's loyalty and courage are tested as they try to understand the supernatural world around them as well as their relationship.