Seth Gendrickson has worked for the Catholic Church's Order of Mount Sion since his initial encounter with a vampire during seminary years ago. Finally working his way up to the rank of Hunter, Seth's first assignment is to investigate a spike in vampire activity in Kansas, an area previously quiet. The region between the Rocky Mountains and the Mississippi River had been a kind of neutral zone for the two main factions - The Assembly of Cairo and Los Muertos. The Assembly hails from Europe, and although few in numbers, is the older of the sects and far more powerful. Los Muertos saw opportunity in the New World, so they established themselves in the Americas and began to multiply. They are young, aggressive, and passionate.
And they're moving east.
Seth is under orders to figure out what's going on before an all out vampire civil war brings knowledge of such supernatural creatures into the open and causes societal panic, a situation the Church is keen to avoid. During his mission, Seth captures one of the enemy and interrogates it, but he soon finds that the movement east is less an invasion than it is an influx of refugees fleeing a greater threat. Something is hunting the vampires out west, something more terrifying than the risk of conflict. Seth tracks this threat from California to Japan and across Europe to discover the heart of a conspiracy that stretches back 2,000 years and threatens the future of the world.