After losing her sister to a serial killer years earlier, scientist Mia Lindgren survives by focusing on the most dangerous viruses known to man. She's become adept at shutting herself off from human contact-until her lab partner drowns under suspicious circumstances. Forced to accept the assistance of Nick Doyle, an FBI counter-terrorism expert on leave, she soon realizes someone at the Institute is involved in a deadly deception. As she and Nick race to find a killer who will stop at nothing to accomplish his version of Armageddon, they can't ignore their own chemistry. But can Mia truly put the past to rest?