Scott McCall, a high school student living in the town of Beacon Hills has his life drastically changed when he's bitten by a werewolf, becoming one himself. He must henceforth learn to balance his problematic new identity with his day-to-day teenage life. The following characters are instrumental to his struggle: Stiles, his best friend; Allison, his love interest who comes from a family of werewolf hunters; and Derek, a mysterious werewolf with a dark past. Throughout the series, he strives to keep his loved ones safe while maintaining normal relationships with them.

Rita heads to the mountains to get some peace and recover from mental distress. While there she meets Pierce, a doctor doing stem cell research whose experiments have gone horribly wrong. Now Rita is the only one who can solve the problem.