A deadly disease from an unknown origin... Addison Kittner and ex-FBI agent Cooper Daine arrive at Bone Clan expecting a warm welcome. Instead they're imprisoned and placed under quarantine, where they discover that the werewolf mountain Clans are being decimated by a deadly plague which can't be cured. An old obligation that changes everything... With only a few days to live, Cooper's brother, Alpha of Bone Clan, asks Cooper to fulfill his promise, one that's crucial to their Clan's survival. But if he does, Cooper risks loosing Addison. Forever. An ancient creature bred for genocide... Determined to stop the plague and cure Cooper's brother, Addison defies Clan law and sneaks away to an ancient ruin which might hold the key. There she discovers an unexpected link to her past and inadvertently calls forth an immortal monster that will destroy the paranormal races protecting humanity if it can't be stopped. But as Cooper and Addison battle to stop the annihilation of the Clans and the forces trying to tear their bond apart, something even more powerful and deadly gathers just out of sight... And prepares to strike.