The first movie is a pretty straightforward buddy comedy. There is the straight man, played expertly by Albert Brooks, and the comic relief, played surprisingly well by Michael Douglas. They are thrown into strange situations together where, almost without fail, Brooks gets nervous and Douglas goes over the top. And the two of them, together, are hilarious polar opposites.

This is cinema’s most popular modern approach to comedy. Just think about some of the recent comedies to tour the country. “Anger Management” had the nervous businessman and the eccentric anger management specialist. “Analyze This” and “Analyze That” featured the reserved psychiatrist and the hot-blooded mafia goon.

But then, as is so often the case with popular movies, a contrived and, honestly, unbelievable story gets in the way. The second movie vying for attention in “The In-Laws” is a spy story, where Douglas serves as an undercover CIA operative, carrying out dangerous operations and flying to various countries without anyone in his life aware of his true identity.

The two opposites – the shy Brooks and the crazy Douglas – meet due to a wedding. Douglas’ son is marrying Albert’s daughter, and after Brooks mistakenly stumbles upon Douglas in action, they must flee a crime scene together. Along the way, they must parachute off a building, use a jet ski to divert a torpedo fired from a submarine and must distract the attention of a sexually ambiguous arms dealer.

Several of these sequences do connect and are very funny. One of my favorites involves the last item mentioned in the previous paragraph. Brooks, using the identity of a respected and famous arms trader, must accept the flirtations of another male arms dealer while Douglas carries out his mission in the background. I must admit, I chuckled.

The success of such scenes is due solely to the acting. Based on the original 1979 movie, which I admit I have never seen, the writing in this film is simply awful. It is one thing to create an unlikely scenario, sprinkle in some comedic lines and double takes, and send everyone away with a good laugh. In 2003’s “In-Laws,” many scenes are so far-fetched that their absurdity, in some instances, cannot be overcome. We are simply dumbstruck at how preposterous this whole episode is.

No, when it works, it is not due to a clever team of writers. The greatest strength of this film is its acting. Douglas, in a role than seems like a far departure from his previous work, hams it up. He uses exaggerated expressions and gets caught up in the melodrama. And Brooks genuinely seems like the nice guy next door who has inadvertently stepped onto a wild ride. He plays the straight man perfectly and snaps back at Douglas just as we’d expect an innocent by standard to react to the craziness that fills this film.

So why then does “The In-Laws” divert attention away from its star players? Why, in a comedy, is there such an extended subplot involving international arms dealers, the FBI, the CIA and a rogue nuclear submarine?

The answer is a simple one: The filmmakers did not have enough material. Many comedies simply do not have enough to keep the story going on purely comedic grounds, and they soon digress into scenes of drama or tension to establish an artificial sense of momentum. If they can’t make the audience laugh, it seems, then a car chase will fill the void nicely.

There is an unexpected consequence to this formula. When attention is stolen away from the comedy, away from this fake world of exaggerations and silliness, and instead diverted to a story of guns and death threats, the bubble of comedy bursts. In these moments, as a character has a gun put against his head, “The In-Laws” starts to take itself seriously. And as soon as that happens, it falls flat on its face.

Something is to be admired about an Adam Sandler comedy. While it’s stupid, it knows its place. A film like “The In-Laws” refuses to decide between silliness and seriousness, and suffers from this indecision. The audience is never sure how to take it and, while they may laugh, no one will ever invest into the story.