The once ubiquitous Jack Black continues to surprise with his leading role in “The D Train” as sad-sack Dan, a married guy who, despite being married to a cute woman and having two kids and a decent job, feels and acts like a dork. The militant chairman of his high school reunion committee, he can’t move past who he was back then, and even the other committee members won’t hang out with him.

When Dan spots former classmate Oliver Lawless (James Marsden) in a national TV commercial, an obsession is reborn. Lawless was the coolest guy in high school and Dan determines that if he can get him to attend the reunion, the event’s success will be assured and Dan’s status will skyrocket.

James Marsden and Jack Black have a complicated relationship in “The D Train.”

James Marsden and Jack Black have a complicated relationship in “The D Train.”

This is an amusing comic idea and we assume that somehow things will get out of hand. Dan invents a business trip to take him to Los Angeles, where Lawless lives. Dan’s longtime boss (Jeffrey Tambor) is behind the times and averse to technology, making it especially easy for Dan to invent a fake business deal. When Tambor decides at the last minute to join Dan, however, he should have bailed on the plan. Of course, the men press on.

Dan’s night out with Lawless goes surprisingly well, and while Lawless is handsome and worldly, he is every bit as unsatisfied with his life as Dan is his. The men bond and then some and, when Dan needs someone to play the businessman he’s pretending to introduce to his boss, Lawless naturally fits the bill.

After a successful, if fabricated, business deal, the misguided gentlemen head out for a drug-and alcohol-fueled night on the town. High on attention and cocaine, Dan gets swept along when the occasion unexpectedly shifts from bromance to romance. I was as shocked as Black’s character when things took this turn.

For the bisexual Lawless, it was just another one-night stand, but married, heterosexual father Dan’s world is rocked. Returning home, he must contend with the professional ramifications of his fake business deal, the impending reunion and his own feelings for Lawless.  

“The D Train” isn’t your usual, raucous Jack Black vehicle. Rather, there’s an unexpected depth of drama in this weird little film. Some of the plot elements stretch the limits of plausibility, particularly if you’re expecting the film to be funny, as I was. However, the pudgy leading man faced some serious dilemmas and wrung a great deal of pathos from his poor decisions.

Even when things were at their most unlikely, the cast didn’t stop believing. Marsden was a hot, smarmy mess, nonchalantly cruel yet compelling. Kathryn Hahn was an important counterpoint as Dan’s wife, who attended the same high school but turned out as a more successful, mature adult.

The biggest standout about this film was the treatment of the details of the hookup. The only problem presented is that Dan is married; the crisis of gender preference isn’t really explored. That Dan’s concern isn’t “I’m gay?” but “I cheated” is pretty revolutionary. I’m not sure how realistic it is, but it’s certainly noteworthy. In the end, the biggest surprise might just be what isn’t presented on screen.

“The D Train” is now playing at Wynnsong 16, Mobile Stadium 18 and Carmike Wharf 15.