The FBI joins detective Alex Cross in a particularly unsettling investigation: two San Francisco joggers have been viciously murdered and are found suspended by their feet, with all the blood drained from their corpses. And when further brutal deaths follow in California and on the East Coast, Alex is forced to contemplate the bizarre possibility of modern-day vampires, although his instincts point him to one of the many sinister religious cults that flourish on the West Coast. Aided by Jamilla Hughes, a streetwise young woman detective from San Francisco, Alex finds that he has to crack not one but two impenetrable mystereis to stop further bloodletting.