As the mysterious Shadow builds an army of demons, Grubbs Grady and his team search desperately for answers. But when they follow up on a new lead, it takes them to an old, unexpected foe-- the Lambs.

As Bec's relationship with Dervish improves, werewolves and demons attack and she sends Shark and Meera through a window to another universe to seek Beranabus, and soon all must face an even greater force of evil, the Shadow.