“The Source Code” opened Friday, starring Jack Gyllenhaal (“The Prince of Persia”) and Michelle Monaghan (“Eagle Eye”).

The story starts off with Gyllenhaal waking up on a train and Monaghan telling him that she “took his advice.”

Gyllenhaal's character (Captain Stevens) informs Monaghan's character (Christina) that he has no idea who she is, and that he is a helicopter pilot involved in Afghanistan.

She keeps calling him “Sean,” and thinks he's joking about being Captain Stevens. The train is outside of Chicago and eventually explodes, due to a bomb being detonated on the train.

After the explosion, Captain Stevens wakes up in a small capsule, strapped to a chair. A female military officer by the name of Captain Goodwin (played by Vera Famiga, known for her role in “Orphan”) explains to him that he is part of the “source code.” He learns that the source code puts him in an alternate reality and in the body of a teacher that was on the train, named Sean.

She then charges him with the task of finding the bomb and the bomber, forcing him to keep reliving the same eight minutes before the explosion over and over again until he completes his mission.

As time goes on, Captain Stevens becomes more interested in saving Christina, his romantic interest.

The designer of the source code introduces himself as Dr. Rutledge (played by Jeffrey Wright, known for his role in the latest “007” films) to Captain Stevens and informs him that what happens in the alternate reality has no bearing on what happens in real life.

Determined to rescue Christina and the other passengers, Captain Stevens makes it his mission to try to save them, no matter what reality they are in.

“The Source Code” starts off with a slow opening scene of the landscape around Chicago. Once the unnecessarily long scene is over, the action begins. It doesn't take long to get to the first train explosion, and the film is nothing but action and twists from there.

Captain Steven's character develops wonderfully as he goes from not knowing his surroundings to working hard to stop the bomber and save Christina. Gyllenhaal gives a spectacular and very convincing performance.

Monaghan's character isn't the typical damsel in distress though, and although her character resets every time the train bombing restarts, she still finds room to develop as a character well.

The other characters on the train are a little flat and aggravating, but that's okay because they're just minor characters.

Captain Goodwin herself comes to feel guilty over sending Captain Steven's back into the bombing as she sees it starts to take a toll on him.

The antagonists of the film are the weakness. The bomber turns out to be a generic insane villain with no past, development or ties to any of the other characters, and Dr. Rutledge is a cold scientist who wants nothing more than for his source code project to succeed. Both characters are flat, predictable and frankly could have used a little more motivation or back story.

Another complaint about the movie is some of the twists. Captain Stevens relived the bombing several times, and each time he understood another piece of the puzzle, but some of the twists seemed pointless and even unnecessarily violent. The audience knows that Captain Stevens is desperate, but he assaults a lot of characters for no reason.

Other than the flat antagonists and a few questionable plot twists, the movie does a good job of entertaining the audience and keeping them guessing who the bomber is.

One of the best parts about the film is how the plot shifts from “find the bomber” to “save the love interest and the other passengers.”

It's that shift in plot that keeps the movie from becoming a stale and forgettable action flick.

The ending to the movie is amazing, and it’s a great payoff to see the ending come after the audience has worked their way through all the plot twists and action scenes of the movie.

Then, there's one great flaw that just serves no purpose, aggravates the audience and ultimately knocks the movie down a notch.

The very last scene (the one AFTER the scene where the movie should have ended) serves no purpose except to leave it open for a sequel. The ending before the last scene is perfect and could not be better, but the greedy producers of the film had to tack on the last three or four minutes just in case they wanted to make more money with a sequel.

It’s amazing how quickly the audience can go from extremely pleased with what they think is the ending, to completely peeved after seeing the producers' blatant attempt to leave the movie ending “open” for a sequel.

Without the last scene, the movie would have gotten a better score, but since the producers made that grave mistake, “The Source Code” gets a 6.5/10.