Starring Ashton Kutcher and Amy Smart. Rated 14A.

Although Dan Savage would probably disagree, Ashton Kutcher's eyelashes and abs are not enough to make him convincing leading-man material. His grinning, slacker-puppy persona seems particularly off-key with The Butterfly Effect's darker explorations of fate. The last thing you want when you're trying to build a supernatural thriller is some goof wondering, "Dude, where's my time-travelling psychogenic ability to alter destiny?"

Named for the part of chaos theory that says even tiny events can alter the universe, the Vancouver-lensed film follows Evan Treborn. As a child, he blacks out every time something traumatic happens, which is a lot. This guy attracts bad luck the way Paris Hilton attracts farm boys, whether it's witnessing childhood pranks going murderously wrong or having his institutionalized, insane father (Callum Keith Rennie) lunge at his throat. Years later, as a psych major, Evan is reunited with one of the girls who shared his pain (Amy Smart), and her sad situation leads him to a discovery that's best left unanalyzed: by reading through his old, unfinished diaries he can actually return to the events that were erased from his memory, and even try to alter them. But as those who have seen anything from Final Destination to The Twilight Zone know, you can't tamper with the past or something else goes awry.

Writer-directors Eric Bress and J. Mackye Gruber's trick is in moving things along quickly and suspensefully enough that you're often too busy being entertained to question how preposterous the premise is. One main drawback is that they resort to such clichéd scenarios: if characters aren't sorority sisters, they're crack whores; jails make Oz look like a holiday resort; and insane asylums look straight out of the 19th century. Another is that Gruber and Bress exploit such distasteful themes as prison rape, animal torture, and kiddie porn as scare tactics. (That last one is abetted by a particularly embarrassing cameo by Eric Stoltz, who swills Scotch oh so threateningly.) Such unsubtle treatment of sick subject matter isn't helped by Kutcher, who seems to treat everything with the same dazed and confused tone.

Obviously, the actor (who's also one of the exec producers) is trying to reinvent himself beyond the permastoner he plays on That '70s Show. Although his legion of teen fans, and maybe Mr. Savage, will undoubtedly flock to the film, those looking for a creepy-smart supernatural mindfuck might end up feeling Punk'd.