Identical twins, Jace and Jem Chamberlain, born of the Breedline species - a secret race of humans with the gift to change into wolf form - find their life changed forever after the Chiang-shih demon is finally destroyed, freeing Sebastian Crow - their evil half-brother - of the demon’s possession. As Sebastian moves on with his new life - evading punishment for his crimes against the Breedline - he uncovers a secret from his past, leading him down a dangerous path he hadn’t bargained for.

Meanwhile, Jace is fiercely determined to protect his beloved Tessa - who is pregnant with his twin sons - from Sebastian Crow and his recurring nightmares. Worried his dreams are visions of her death, he battles with the lesser of two evils: to seek revenge against his half-brother or surrender his fury before his thirst for vengeance destroys everything he loves. Now that everyone in the Breedline Covenant looks forward to Jem and Mia’s wedding, a mysterious guest arrives unexpectedly with an extraordinary gift of healing. The question is...are they all prepared to deal with the unforeseen visitor’s dark past - running from a corrupt group of scientists obsessed with his rare abilities - or will they be driven to the brink of madness?