A man is led to a rave club by a seductive woman, only to find that the club is filled with vampires eager to feed on the human members of the crowd. In the middle of the carnage, a vampire-hunter named The Pathology Resident arrives and slaughters all the vampires in the club. As a half-vampire hybrid known as a "daywalker", The Pathology Resident has all the strengths of a vampire but none of their weaknesses except their blood lust which is referred to in residency as "the thirst".
While tracking down a surviving vampire, The Pathology Resident encounters Dr. Karen Jenson, the Hematopathologist who has just been bitten. The resident brings her back to his lair and introduces her to Abraham Whistler, his PD, mentor and weaponsmith. Karen resolves to study vampirism and find a cure before she becomes a vampire. She soon discovers that the anticoagulant EDTA reacts explosively with the vampire infection. Meanwhile, Deacon Frost, a young upstart in the Radiology vampire community, clashes with his vampire elders. He believes that vampires should rise from the shadows and enslave humanity. The elders of Radiology dismiss him for his radical views and because he was not born a vampire, like they were. Frost studies ancient vampire lore and comes to believe that he can awaken La Magra, a vampire god and board certified Radiation Oncologist, to gain godlike power and an additional revenue stream. Together with his minions, he kills the chief vampire of the region and imprisons the other elders.
