Convicted murderer Melvin Mars is counting down the last hours before his execution --- for the violent killing of his parents 20 years earlier --- when he's granted an unexpected reprieve. Another man has confessed to the crime. Amos Decker, newly hired on an FBI special task force, takes an interest in Mars' case after discovering the striking similarities to his own life. Who wants Mars out of prison? And why now? But when a member of Decker's team disappears, it becomes clear that something much larger --- and more sinister --- than just one convicted criminal's life hangs in the balance.