| Director | Ivan Reitman |
|---|---|
| Genre | buddy film, comedy film, science fiction film |
| Runtime | 102 min |
| Country | United States |
| Budget | $15 million |
| Box office | $216.6 million |
A secret genetic experiment attempts to produce the perfect child by combining the DNA of several distinguished individuals. The embryo unexpectedly split, resulting in twins: Julius and Vincent Benedict. Their mother, Mary Ann Benedict, is told that Julius died at birth and is never informed of Vincent's existence. The boys are raised separately, each unaware of the other. Julius is taken to a remote island and raised by one of the scientists. He grows into an optimistic, physically imposing, highly educated man, though he remains naïve about the outside world. Vincent, meanwhile, is abandoned at a Los Angeles orphanage and grows up alone, becoming a short, balding, cynical small-time criminal.
On Julius's thirty-fifth birthday, he learns of Vincent's existence and travels to Los Angeles to find him. He locates Vincent in jail and bails him out, though Vincent is skeptical of Julius's claim that they are twins, given their obvious physical differences. After Julius protects him from loan sharks, Vincent begins to accept him. Vincent introduces Julius to his girlfriend, Linda Mason, and her sister Marnie. While Linda reluctantly tolerates Vincent's lifestyle, Marnie dislikes his selfish treatment of her sister. Julius, inexperienced with women, fails to notice Marnie's attraction to him.
Vincent reveals a document suggesting their mother did not die in childbirth, but refuses to search for her, convinced she abandoned him. Soon afterward, he steals a Cadillac, intending to sell it, only to discover a prototype fuel injector hidden in the trunk. Realizing it was meant to be delivered to wealthy industrialist Beetroot McKinley in Houston for $5 million, Vincent decides to deliver it himself and collect the payment to settle his debts. Meanwhile, Webster, the ruthless courier originally responsible for the delivery, begins tracking Vincent down.
Encouraged by Julius's optimism about finding family, Vincent reluctantly agrees to search for their mother while traveling to complete the delivery. They locate one of the scientists involved in their creation, who directs them to an art colony near Santa Fe where Mary Ann lives. The scientist dismissively calls Vincent a genetic failure, prompting Julius to defend his brother angrily.
At the colony, the twins speak with a woman who claims Mary Ann Benedict has died. In reality, she is their mother, but she dismisses their story as a cruel joke. Hurt and convinced he was unwanted, Vincent abandons Julius and travels to Houston alone to deliver the injector.
In Houston, he attempts to complete the exchange, but is confronted by Webster, who murders McKinley and attempts to take the money. Julius arrives and pursues Webster through the building while Vincent initially escapes with the payment. Realizing he cannot abandon his brother, Vincent returns and offers the money to save them. When Webster prepares to kill them anyway, the brothers work together to defeat him.
Afterwards, Vincent gives the injector and the money to the authorities, while secretly keeping $1 million. The brothers reconcile and start a consulting business together. News reports about the unusual twins reach the art colony, where Mary Ann realizes they are her sons. Mary Ann finds and tearfully reunites with them. Julius and Vincent later marry Marnie and Linda, and each has twins of their own.