"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.

Maria never knew he possessed the Power of Exorcism, which enables him to kill vampires. Now with Mary's help, Maria digs into his past and unearths "Red Memories" that he had suppressed. Meanwhile, Mary begins to recover missing memories of his own. What truths await the exorcist and the vampire, and could their lives have intersected in the past?