When a sniper begins targeting young victims, the team is forced to retrace the steps of the past in order to solve this modern day mystery.

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.

Rebecca, Doc, and Hauser set out to capture musically-inclined serial killer Webb Porter, an unknown ’63 that returns more violent than ever.

Doc and Rebecca close in on a man who may be the key to revealing the secrets behind all the returning criminals. Meanwhile, Hauser makes a discovery beneath the halls of Alcatraz that brings him ever closer to the truth.

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.