When child killer Kit Nelson, a terrifying kidnapper who always returns his victims home - after he's killed them - reappears from the past, the team is in a race against time to catch the man before he kills again.

When Hauser, Madsen, and Soto track former inmate Paxton Petty, a landmine bomber who has returned and is placing bombs throughout populated areas of San Francisco, methods of the past are applied to the present.

Revealing doors are opened and lives hang in the balance as Rebecca will stop at nothing in pursuit of the man who killed her partner.