What do the films "Inception," "Unlimited" and "Source Code" have in common? They're all concept films, futuristic and with three of our best male actors as the protagonists. Of the three, this one is, arguably, the most consistent, least flawed and runs the perfect length.

The concept in this case is that eight minutes of memory data remains in the minds of the dead and it's readable by Dr. Rutledge's (Jeffrey Wright) recently developed computer algorithm called the Source Code. Through that technology, the event that killed the people traveling in a train bombed by a terrorist can be played and replayed with the insertion into it of an also dead military investigator. The investigator, working now on the first source code mission, may experience it as reality, if only in an eight minute increment of it.

Decorated Afghan war hero Captain Colter Stevens (Jake Gyllenhaal) is the investigator who has been chosen for that task: return to the bombed commuter train heading for Chicago, find the location of the bomb, the identity of the bomber and, by relaying this information to his handlers, preventing the detonation of a much larger bomb in downtown Chicago, as warned in a letter from the bomber. And, time is running out.

In his first trip back in time, Colter awakens as though coming out of a nightmarish dream. He sits on the train facing a fetching woman named Christina Warren (Michelle Monaghan) who thinks she knows him. "I took your advice and it worked," she says as though he never left his seat. This is because when she looks at him, she's seeing her traveling companion, George Troxel. Stevens discovers this when he looks in a mirror.

It's a good thing that we see Gyllenhaal, though, because he's so good for this part -- a superbly sympathetic actor. But, I digress.

After a brief conversation in which he's anything but comfortable about being where he is and being addressed as someone else, he takes note of individuals aboard the train. The bomb explodes and he finds himself in a grey tomb-like enclosure much like a pilot training module. His return is even more traumatic than his awakening on the train but, as he settles down, he becomes aware of a voice. There, on a monitor, he's being addressed as who he really is by a woman in military uniform. She is Colleen Goodwin, (Vera Farmiga) his mentor, or guide. She explains what he's just experienced and what his assignment is when he returns to the train.

In doing so, her dialogue is well designed to inform us of the futuristic concept of the film. We now are avid followers of Colter as he returns several times to the ill-fated train with growing control over his awareness and effectiveness in his role. He finds the bomb; finds romance with Christina who has been friendly and inviting from the git go; grows suspicious of wrong people; remembers everything from prior missions as well as strategies decided while back in the source code pod. The reliving of the train experiences being so vivid, he begins to think that he can beat all the assumptions about being dead and the possibilities of the source code itself.

But can he? Does he complete his mission to find the terrorist as the urgency grows critical? Will it be all for naught? Does his ultimately falling in love with warm, affectionate Christina amount to anything in the real world? Come and see. All your questions will be answered.

But there's no question that director Duncan Jones, working from a tight script by Ben Ripley, has come up with an intriguing and galvanizing suspense thriller that is superbly realized with an ace cast and a flawless production. Editing is a major factor here and Paul Hirsch's work is frame perfect. Cinematographer Don Burgess's lighting, varying between the warm tones of the pseudo reality and the cold desaturated blueness of his training pod, often intimate and close up, is pure artistry. Chris Bacon provides the taut, compelling score.

Jeffrey Wright plays the source code's inventor Dr. Rutledge from the perspective of the man with most to lose if the mission proves a failure. His concerns provide another layer of pressure to the anxieties that bear an inhuman aspect, while Farmiga provides a balance on the scale of sensitive humanity. But, my true hero on a natural conveyance of compassion goes to Gyllenhaal. Few actors compare to him in a natural assimilation of physical toughness and sensitivity, both of which he manages with seamless empathy.

The concept has been compared to "Groundhog Day." But, it owes more, in setting and content, to two other predecessor sources: author George D. Shuman's "18 Seconds" and TV's science fiction series, "Seven Days."

This is the sort of what-if scenario that envelops our senses like tantalizing fiction should. Hearing the concept without being immersed in what Jones made of it might raise rather heavy doubts about how well it could work. All the greater reason to praise the skill that shaped it with such brisk force and loving hands.

                                      ~~  Jules Brenner