Asher Blackthorn is a young but weary rookie police officer whose older brothers recently died of complications related to muscular dystrophy. His dismal world explodes into chaos one fateful night when he encounters Icarus, a sadistic living vampire, whom he somehow kills with a lucky shot through the eye.

Impressed by his skills with a firearm, Commander Micheal Greaves of the 96th Legion abducts Asher and attempts to convince him to enlist. Asher reluctantly decides to join the Legion, becoming part of a covert paramilitary force dedicated to the downfall of Atropos, a criminal organization led by living vampires.

Unbeknownst to Asher, his oldest brother Cyrus Blackthorn still lives and is taken from his home by associates of CyberGen, a bioengineering corporation with a disturbing lack of morality. Placing him on the operating table, CyberGen's researchers present Cyrus with a choice: he can return to his life to await a slow death or undergo an experimental procedure, one that could cure his disease. Agreeing to the procedure with little convincing, Cyrus awakens to find himself cured, though at a high cost: he will mutate and lose his humanity entirely.