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 contactuntil 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?