Deacon Hatchett and his partner, Verity Bishop, are Missionaries—though not in the modern sense. Missionaries are tasked with the tracking and killing of Angels: horrific beings of geometry and anatomy that can hardly be given justice by mere words. The only thing that separates them from average humans is their affinity for Ether, an energy that permeates the air of Earth. For 2,000 years has humanity been waged in ceaseless warfare with these beings. It is now the mission of Deacon, Verity, and the people they meet during their journey to unravel the threads of a two-millennia-old mystery. If they're successful, their species will be able to roam the world without constant fear of death. If they fail, however, the coming age as described in ancient texts may arise: the resurrection of a Seraph—and as a result, the end of times.