The story begins with a framing device in which efficiency trainer Frank Allen (Ryan Reynolds) talks to his skittish soon-to-be son-in-law. Frank assures the kid that chaos is a part of life, and as proof, he relates the story about his marriage to Susan (Emily Mortimer). They meet cute, get hitched, and have a child. Frank's life unravels one day when he misses a ferryboat. This causes him to be late for a Time Management training he's conducting, which causes him to confess his woes later that night to a sultry convention attendee (Sarah Chalke), who instantly puts the move on him. Through the kind of mix-up that fueled many an episode of "Three's Company," Susan comes to believe that Frank is cheating on her, and she throws him out.

Susan also comes to think that he has impregnated a different woman, which causes Frank to get a DNA test that yields surprising results that do nothing to help his marital state. Compounding all this is Frank's best friend, the appropriately named Buddy (Stuart Townsend), who causes even more complications by virtue of the fact that he's in love with Susan himself.

As you can see, Chaos Theory remains true to its title, in that a lot of things "cause" other things to happen until poor Frank is stuck in a whirlpool of insanity. By the end of the film, he's so far off the deep end that he even purchases a hunting rifle and plans to use it on someone else.

I guess the first thing I should say is that Ryan Reynolds is pretty good in this role. Coming from me, that's a compliment. For years, my friends and I have shared a private joke about the "Ryan Reynolds Rule," which states that no movie starring the actor is ever any good. Chaos Theory has its flaws too, but Reynolds shows some growth as an actor here. He's not coasting on the autopilot charm he relied on in pictures such as Waiting and Van Wilder. In spite of some problematic scripting, he works hard to give a genuine performance.

Too bad the movie undercuts him at every turn. Chaos Theory always seems confused as to what kind of story it wants to be. The early scenes border on farce as poor Frank tries to dig himself out of a comic situation that increasingly gets worse. The harder he tries to explain himself to Susan, the deeper his hole gets. Then, in the second half of the film, everything gets surprisingly dark. Once the paternity test yields its results, Frank really goes off the deep end. He stops being a hapless goof and turns into a borderline psycho. The pinnacle is a scene set on a rowboat in the middle of a lake, with two people and a gun inside.

It's hard to successfully mix wacky humor and melodrama. (Tyler Perry usually manages it with his pictures, but few others are able to pull it off.) Watching Chaos Theory, I couldn't help but reflect that it would have been better had it stuck with one thing or the other. A comedy of complications would have been just fine. So would a heavy drama about infidelity and marital connectedness. But by trying to be two opposing things simultaneously, director Marcos Siega gives us a picture that is neither fish nor fowl. The cast is good and the themes are compelling, but the execution is a bit of a mess.

( out of four)

DVD Features:

Chaos Theory arrives on DVD June 17 with the widescreen version on one side and the fullscreen version on the other. The only special feature is a short selection of deleted scenes that, again, emphasize the good performances and uneven tone.

Chaos Theory is rated PG-13 for mature thematic material, sexual content and language. The running time is 1 hour and 28 minutes.