After solving two cases in her first months with the FBI, Peyton feels things are beginning to come together in her career. Her personal life is another matter. Although Marco has shown signs he wants to work on their relationship, building trust will take time. However, that progress is put on hold when an American college student is killed in London. Peyton and the Ghost Squad must venture across the pond to solve the murder and catch a killer that grows bolder with each attack, leaving only a single clue behind... ...the howl of a werewolf.