Detective Rebecca Madsen and Dr Diego Soto join forces with a secret agency charged with catching recently resurfaced Alcatraz inmates.

When child killer Kit Nelson, a terrifying kidnapper who always returns his victims home after he's killed them, reappears, the team race to catch him before he kills again.

When a notorious robber returns from the past, Rebecca must extricate him from a hostage-filled bank before his identity is discovered.

An Alcatraz guard, Guy Hastings, reappears and runs into an old acquaintance. He is asked to perform an evil deed.

The team use methods of the past to track former inmate Paxton Petty, who has returned to plant bombs in populated areas of San Francisco.

Madsen and Hauser look for a killer with a background in chemistry who likes to poison his victims; more information about Madsen's grandfather comes to light.