An ambitious genetic experiment takes the wrong turn when two twins, who look nothing alike, are born and then separated. Years later, the unlikely siblings meet, Julius (Schwarzenegger), a highly educated but sheltered giant with a big heart, and Vincent, a pint-sized hustler with an insatiable lust for women and money. With girlfriends in tow and a hitman on their tail, the new-found brothers set off on a wild, cross-country misadventure to find their mother, but end up finding out more about themselves...