Agent Maggie O'Dell and Assistant Director Cunningham believe they're responding to a threat made at Quantico. Instead they walk into a trap. Before they realize it, they've both been exposed to a killer who can strike at anyone, at any time, and no one can predict who might be next…until it's too late. The killer's tactics suggest he's an aficionado of criminal minds. He uses bits and pieces from those he admires: a phrase from the Beltway Snipers, a clue from the Unabomber, a delivery method similar to the Anthrax Killer. His weapon is a deadly virus, virtually invisible and totally unexpected. His victims appear to be random but, in fact, they are chosen with a revengeful precision. The vaccine is limited and untested.