Source Code is a 2011 science fiction action thriller film[4] directed by Duncan Jones and written by Ben Ripley.

It stars Jake Gyllenhaal as Captain Colter Stevens of the U.S. Army, who is sent into an eight-minute virtual re-creation of a real-life train explosion, and tasked with determining the identity of the terrorist who bombed it.

However, to the world around him – including his friend Christina Warren and his reflection in the train's windows and mirrors – he appears to be a different man: a school teacher named Sean Fentress.

Stevens again reawakens in his capsule and after demanding to be briefed, learns that the train explosion actually happened and that it was merely the first attack of a suspected series.

Rutledge explains that the Source Code is an experimental machine that reconstructs the past using the dead passengers' residual collective memories of eight minutes before their deaths.

After numerous attempts, including being arrested by train security for trying to obtain a weapon, Stevens identifies the bomber through a fallen wallet as the nihilistic domestic terrorist Derek Frost.

Outside the Source Code, Stevens relays his knowledge to Goodwin, which helps the police arrest Frost and prevents the second attack.

Being more sympathetic to his plight, Goodwin sends Stevens back one last time and promises to disconnect his life support after eight minutes.

As the world around him continues to progress beyond eight minutes, Stevens confirms his suspicion that the Source Code is not merely a simulation, but rather a machine that allows the creation of alternate timelines.

[7] In an article published by the Writers Guild of America, screenwriter Ben Ripley is described as providing the original pitch to the studios responsible for producing Source Code:[8] Ripley first came up with the idea for Source Code, in which government operative Colter Stevens repeatedly relives the eight minutes leading up to a terrorist train bombing in hopes of finding the bomber, he had no intention of writing it on spec.

"[10] In the ending scene, Jake Gyllenhaal and Michelle Monaghan's characters are seen walking through Millennium Park and making their way to the Cloud Gate.

[25] Despite its grosses, according to director Duncan Jones, the studio claims that the film has never turned a profit, which is attributed to Hollywood accounting.

The site's consensus reads: "Finding the human story amidst the action, director Duncan Jones and charming Jake Gyllenhaal craft a smart, satisfying sci-fi thriller.

"[5] Roger Ebert gave the film 3.5 stars out of 4, calling it "an ingenious thriller" where "you forgive the preposterous because it takes you to the perplexing".

[35] Kenneth Turan of the Los Angeles Times called Ben Ripley's script "cleverly constructed" and a film "crisply directed by Duncan Jones".

[36] CNN called Ripley's script "ingenious" and the film "as authoritative an exercise in fractured storytelling as Christopher Nolan's Memento".