When I came home from seeing Source Code on May Day evening, I turned on the TV and heard that Osama Bin Laden had just been captured and killed by the Americans.

The film I had just watched dealt intimately with terrorism, and I couldn’t help thinking, with the news from Pakistan, and the Canadian election one day away, that a historic corner had been turned.

Subsequent events have borne this out, and I’m pondering today whether the technology employed in Source Code already exists, or is just around the corner.

It’s a fascinating and frightening film, with elements of Inception andGroundhog Day all mixed in, and it makes for absorbing viewing.

Jake Gyllenhaal, most recently seen in Love and Other Drugs (and who turned in such a memorable performance in the groundbreaking Brokeback Mountain), stars as Captain Colter Stevens, an American soldier assigned to Afghanistan, who is on a classified mission to avert a potential disaster.

Without giving too much of the plot away, he has been catapulted into the body of a Chicago teacher who is riding on a full commuter train on a sunny spring morning.

The train is a terrorist target, and is about to explode. Captain Stevens must find the bomb and establish the identity of the bomber. If he fails, then intelligence sources have determined that the terrorist has a portable nuclear device ready to annihilate the entire city of Chicago.

The catch here is that the Source Code technology that’s in place takes advantage of the supposed fact that the human brain retains a kind of “print-through” memory for about eight minutes before it ceases to function after death.

Captain Stevens’ consciousness is programmed to keep returning to the scene of the train explosion, eight minutes at a time, until he succeeds in his mission.

Like any intelligence-gathering mission, this one is conducted on a “need-to-know” basis. When elements of the Source Code program don’t add up for Stevens, he begins to rebel against his programmers, with fascinating results.

Of course there’s a love interest, played by Michelle Monaghan (Due Date,The Bourne Supremacy) as Christina Warren, a friend of the teacher whose identity has been appropriated by Stevens.

He’s determined to defy the rules that govern the immutability of parallel time-tracks somehow, and save her from the inevitable disaster that faces her and her train-mates.

Source Code is one of the best things I’ve seen since The King’s Speech.

Its appeal lies in the fact that it explores technology that is currently being discussed by leading-edge scientists, and does not spin out into the realm of far-fetched fantasy to try to maintain our interest.

Particularly absorbing is the role of Vera Farmiga (The Departed). She plays Coleen Goodwin, Stevens’ handler for the mission, who is torn between her loyalty to her superiors and his need to fathom what’s really going on with his assignment.

It’s a complex film, and it’s 90 minutes well spent. Source Code plays at 9:00 at the Yukon Theatre and is rated PG for violence and coarse language.