The Butterfly effect

The Butterfly Effect is a 2004 American psychological thriller film that was written and directed by Eric Bress and J. Mackye Gruber, starring Ashton Kutcher and Amy Smart. The title refers to the butterfly effect, a popular hypothetical example of chaos theory which illustrates how small initial differences may lead to large unforeseen consequences over time.

Kutcher plays 20-year-old college student Evan Treborn,[2] with Amy Smart as his childhood sweetheart Kayleigh Miller, William Lee Scott as her sadistic brother Tommy, and Elden Henson as their neighbor Lenny. Evan finds he has the ability to travel back in time to inhabit his former self (that is, his adult mind inhabits his younger body) and to change the present by changing his past behaviors. Having been the victim of several childhood traumas aggravated by stress-induced memory losses, he attempts to set things right for himself and his friends, but there are unintended consequences for all. The film draws heavily on flashbacks of the characters' lives at ages 7 and 13, and presents several alternate present-day outcomes as Evan attempts to change the past, before settling on a final outcome.

The film received a poor critical reception, but was nevertheless a commercial success, producing gross earnings of $96 million from a budget of $13 million. The film won the Pegasus Audience Award at the Brussels International Fantastic Film Festival, and was nominated for Best Science Fiction Film at the Saturn Awards and Choice Movie: Thriller in the Teen Choice Awards.

Growing up, Evan Treborn, and his friends, siblings Kayleigh and Tommy Miller, and Lenny, suffered many severe psychological traumas that frequently caused him to black out. These traumas include being coerced to take part in child pornography by Kayleigh and Tommy's father, George Miller (Eric Stoltz), being nearly strangled to death by his institutionalized father, Jason Treborn (Callum Keith Rennie), who is then killed in front of him by guards; accidentally killing a mother and her infant daughter while playing with dynamite with his friends; and seeing his dog being burned alive by Tommy.

Seven years later, while entertaining a girl in his dorm room, Evan discovers that when he reads from his adolescent journals, he can travel back in time and redo parts of his past. His time traveling episodes account for the frequent blackouts he experienced as a child, since those are the moments that his adult self occupied his conscious. However, there are consequences to his revised choices which dramatically alter his present life. For example, editing his personal time-line leads to alternative futures in which he finds himself, variously, as a college student in a fraternity, an inmate imprisoned for murdering Tommy, and a double amputee. Eventually, he realizes that, even though his intentions to fix the past are good, his actions have unforeseen consequences in the present in which either he or at least one of his friends does not benefit. Moreover, the assimilation of dozens of years' worth of new memories from the alternative timelines causes him brain damage and severe nosebleeds. He ultimately reaches the conclusion that he and his friends will never have good futures as long as he keeps trying to fix the past, and realizes that the only thing keeping his friends from having good lives is himself.

Evan travels back one final time to the day he first met Kayleigh as a child. He intentionally upsets her so that she and Tommy will choose to live with their mother, in a different neighborhood, instead of with their father when they divorce. As a result, they are never subjected to a destructive upbringing, and never grow up with Evan, and go on to have happy, successful lives. Evan awakens in a college dorm room, where Lenny is his roommate. As a test, he asks where Kayleigh is, to which Lenny responds "Who's Kayleigh?" Knowing that everything is all right this time, Evan burns his journals and videos to avoid altering the timeline ever again.

Eight years later in New York City, an adult Evan exits an office building and passes by Kayleigh on the street. Though a brief look of recognition passes over both of their faces, they both decide to keep walking.