Bloody Mary, a vampire with a death wish, has spent the past 400 years chasing down a modern-day exorcist named Maria who is thought to have inherited The Blood of Maria and is the only one who can kill Mary. To Mary's dismay, Maria doesn't know how to kill vampires. Desperate to die, Mary agrees to become Maria's bodyguard until Maria can find a way to kill him.

Mary is not your typical vampire. He can withstand sunlight, holds a reflection in mirrors, refuses to drink blood - and he wants 17-year-old high school student-slash-priest Maria to kill him. In order to do so, Maria must uncover the Power of Exorcism, which is supposed to have been passed down through his bloodline. But while searching for insight into the Power, Maria suspects someone might be sabotaging his efforts.