In the season finale, Doc and Rebecca close in on a man who may be the key to revealing Alcatraz's secrets. And Hauser makes a discovery that brings him ever closer to the truth.
Rebecca, Doc, and Hauser set out to capture the musically inclined serial killer Webb Porter (guest star RAMI MALEK), an unknown '63 that returns more violent than ever.
Clarence Montgomery (guest star MAHERSHALA ALI), the only innocent man in Alcatraz, returns to present day, but is now committingcrimes. Why?
Sonny Burnett (guest star THEO ROSSI), a man with an incredible dark side who became ultra-violent during his stint at Alcatraz returns for another reign of terror.
Two of Alcatraz's most violent brothers, who were notorious for nearly escaping in 1963, find something mysteriously amiss when they return to the island in the present day.
Madsen and Hauser hunt down a vicious killer with a background in chemistry in a race against time before he horrifically poisons more innocent victims.
When convicted bomber Paxton Petty (JAMES PIZZINATO) returns to place bombs throughout populated San Francisco, methods of the pastare used in the present to stop him.
For the first time, an Alcatraz guard reappears. Although he's a good man, Guy Hastings (guest star JIM PARRACK) is being asked todo bad things and will come face-to-face with an old acquaintance.
When a notorious bank robber (guest star ERIC JOHNSON) 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.
When a terrifying child killer, Kit Nelson (MICHAEL EKLUND), reappears from the past, the team is in a race against time to catch the man before he kills again.
A San Francisco detective and an Alcatraz historian team up with a secret agency dedicated to catching inmates who went missing 50 years ago and are mysteriously reappearing today.