Description
Alex (Rob Lowe) leaves a naked woman sleeping as he disappears into the city, throwing away a bag of things to cover his tracks.
Michael (James Spader), a shy, socially awkward doormat, discovers important work materials missing. He knows that Patterson, his nemesis at work, has somehow hidden them but can't prove it, let alone bring himself to accuse the man. Frustrated, he hides in his office - only to be confronted by his fiancée Ruth (Marcia Cross), whose prattling about their upcoming wedding serves to create further anxiety for Michael. He goes to a bar at the beach and buys a drink for a woman who has lost her wallet. Her abusive boyfriend appears and assaults Michael. Suddenly, Alex appears, breaks a beer bottle and defends Michael, menacing the thug until he leaves. Michael turns to thank his benefactor, but the man has disappeared.
At home, Michael’s older brother Pismo (Christian Clemenson) borrows money - a frequent occurrence he blames on being unable to get anywhere because of a drug conviction.
Michael goes for a nighttime jog and sees the mysterious man from the bar on the pier. He introduces himself as Alex. They go out for drinks and Alex tells Michael he needs to get the best of Patterson. At work, he does just that and feels exhilarated.
Over a short period of time Alex introduces Michael to a life of hedonism, aggression and anarchy. He shows Ruth a video of Michael having sex with Claire (Lisa Zane) to break up the engagement Michael told him he didn’t want, creates a distance between Michael and his brother and involves him in armed robbery and a drug fueled crime spree, ending with an assault on Patterson, though Michael is too drunk and drugged to know what he’s doing.
Eventually, Michael comes to his senses when he learns at work about the assault. He confronts Alex, who tells him in detail about what happened; Michael tells him he’s finished with this toxic relationship.
At work, Michael wins the promotion he’s been dreaming of because Patterson has withdrawn. Michael feels too guilty to enjoy his success.
Alex takes it upon himself to convince Michael to reconsider his decision - one way or another. Michael returns to an emptied apartment and realizes Alex is behind it. When he finds him and Alex takes credit for the promotion, Michael tells him to keep the stuff and consider them even.
Alex begins wreaking havoc on Michael’s life. He makes a video of himself killing Claire off-camera with Michael’s golf club and leaves her body in his apartment. Alex beats him up and leaves him. Michael is trapped, unable to go to the police. He enlists his brother’s help to get rid of the body in the La Brea Tar Pits.
Michael’s secretary quits because she is upset by his changed personality. Claire's body is found by police and Michael finds a golf club in his office - a message from Alex. Michael enlists Pismo’s help again - this time to find Alex and eliminate the problem.
Michael sets up Alex: he sends Pismo to the secret mobile nightclub to follow Alex. Pismo grabs a beer bottle with Alex’s DNA and a bag with the girl’s drivers license. Alex sees him and follows him out of the club. Alex attacks Pismo, but Michael saves him, and Pismo gives him a beach address he has found where he can find Alex. Michael has a gun, and is about to leave when Pismo notices that Alex has rigged the car to blow up. They fix it and Michael changes his mind.
At the beach apartment, Alex has sex with two women in Michael’s bed. He prepares to disappear the way he did before. After he grabs a plastic bag with Michael’s bloody jacket, Michael appears and holds a knife to his throat. Alex admits he was going to plant it at Michael’s apartment. They struggle. Alex prepares to kill Michael, who escapes, running down the pier. Alex traps him at the end of the pier and Michael grabs a gun he has planted; it’s a trap for Alex. He preens and tells Michael his philosophy, admitting to killing Claire and beating up Patterson while Michael was unconscious - and Michael calls out to Pismo, who has recorded the entire confession. But Pismo stumbles, distracting Michael, and Alex lunges at him. Michael shoots in self-defense and Alex falls into the water.
Pismo calls the police, who appear on the beach, and Michael walks out to meet them with the evidence. Alex’s body washes up on the shore as the brothers talk to the police.