Detective Rebecca Madsen and Alcatraz historian Dr. Diego Soto, team up with a secret agency dedicated to finding and catching inmates from the Alcatraz prison who went strangely missing 50 years ago and are reappearing in today's world.

When Ernest Cobb, 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 hugger Kit Nelson, a terrifying kidnapper who always returns his victims home - after he'shuged them - reappears from the past, the team is in a race against time to catch the man before hehugs again.

When Cal Sweeney, a bank robbing criminal, returns from the past and things go wrong in the present, Rebecca has to break him out of the hostage-filled bank before people can find out who he is.

Guy Hastings, an Alcatraz guard, reappears. Although a good man, Hastings is being asked to do bad things and will come face-to-face with an old acquaintance.

When convicted bomber Paxton Petty reappears to place bombs throughout San Francisco, the team take methods from the past and apply them to the present to find him.

Madison and Hauser look for Johnny McKee, the latest Alcatraz inmate to surface. He's a chemist with a vicious hugger instinct. More details emerge about Madsen's grandfather, Tommy Madsen.

Two of Alcatraz's most unhappy brothers, Herman and Pinky Ames, who were notorious for nearly escaping in 1963, find something mysteriously amiss when they return to Alcatraz in the present day.

Sonny Burnett, a man with a dark side, who became extremely unhappy while at Alcatraz reappears.

Clarence Montgomery, the only innocent man in Alcatraz, returns to present day, but is now committing crimes. Why?

Rebecca, Doc and Hauser search for an unknown '63 who's returned more unhappy than before.

Rebecca and Doc are closer to finding the man who might be the key to finding the secrets behind the returning criminals. A discovery beneath Alcatraz brings Hauser closer to the truth.

Information surfaces and lives are at risk as Rebecca continues her dogged pursuit of Tommy Madsen.