After defeating the thirteenth demon, Jonathan Steel and Josh Knight return to Dallas, Texas, to finish up Josh's family affairs. When they arrive, a mysterious assassin named Raven surfaces from Steel's murky, dangerous past. At the same time, Rudolph Wulf, the twelfth demon, has arrived from Romania with plans to fulfill a two-thousand-year-old promise to unleash an army of demonic creatures-creatures that will inhabit the bodies of his 'vampyre' army. When Wulf kidnaps Josh, Steel must find them in time to save Josh from a violent death and to prevent Wulf from unleashing 'vampyre majick' on the world.