After the mauled body of a girl shows up on the outskirts of Bear Valley in Upstate New York, Elena Michaels, the world’s only female werewolf, is forced to choose between her new human life (and lover Philip McAdams) in Toronto and the more-than-human existence she’s forsaken at Stonehaven, home to the Pack of werewolves she left a year beforehand.

At Stonehaven, Elena tracks the killer Mutt (the Pack term for rogue werewolves) while avoiding the advances of Clay Danvers, her former lover. Haunted by her own past as a killer, she’s desperate to get back to her human life, but is delayed when a second body is discovered, this time on Stonehaven property.

Old chemistry resurfaces as Elena and Clay work together to track the Mutt to a warehouse rave. But when Elena threatens the Mutt and his fear triggers the Change, they are faced with fighting him in his wolf form, resulting in a deadly blood bath.

With a growing sexual tension between them, Elena and Clay pair up to investigate why psychotic killers are suddenly being “bitten” into werewolves. When their search reveals that old Mutts are working together with newly-turned Mutts, Clay and Elena suddenly realize they’re facing an organized plot to overthrow Pack rule.

Elena’s origins as a werewolf and the history of her love affair with Clay are revealed as she struggles to defend Clay against suspicions of murder. When former Pack member Daniel Santos arrives with information on the Mutt uprising, he takes the opportunity to undermine Elena’s trust in the impulsive Clay.

Back in Toronto, Elena’s commitment to Philip and her human life is interrupted when Santos crashes Philip’s sister’s wedding party, offering her a way out from the strife of the Pack. Her refusal to run away with Santos leads to a gory “parting gift” with shocking revelations. Meanwhile, at Stonehaven, Jeremy is forced to fight to keep his Alpha status.