The program - source code - allows humans to teleport into an alternate universe and enter the last eight minutes of a deceased person's mind. The program also has the capacity to replay the scenario as often as needed.
US Army helicopter pilot Colter Stevens (Jake Gyllenhaal) has been assigned the task of using the source code to solve a train blast, the first in an expected series of attacks on Chicago. He enters the mind of a commuter, then the train blows up. After each failed attempt, the source code is reset and Colter gets another chance.
Between teleportations, Colter returns to a capsule where he's coached on the mission via video conferencing by Captain Goodwin (Vera Famiga).
Watching Colter relive the incident over and over reminds one of Sisyphus and his constant failure to roll the stone up the hill. You could call Colter a failure, but the source code makes up for his flaws, giving him almost endless chances to solve the crime.
Technical jargon aside, the concept of a source code is less far-fetched than it could be. Maybe one day we'll have the capacity to create this kind of a program. Until then, Source Code will keep you entertained, and provide a glimpse into the future.