"Quantum Leap" is an American sci-fi drama starring Scott Bakula as Dr Sam Beckett, a physicist from the future who is the victim of a time-travelling experiment that went awry. Instead of returning to his own period, he travels through time leaping into another person's life, where he often finds himself in dangerous situations. The only company he has on his journey is a hologram called Al (Dean Stockwell), who helps Sam try to right some wrong or misfortune that has befallen the person he is occupying. Each episode ends with Sam time-travelling into the setting for his next adventure. Sam often encounters historically famous faces. He bets on Muhammad Ali beating George Foreman, helps a young Buddy Holly with the words to a song, leaps into a man who looks like Humphrey Bogart and advises a 12-year-old Donald Trump that investing in New York property would be a good way to get rich. In the opening episode, Sam leaps into the body of a 1950s test pilot. It premiered in 1989 and ran for five seasons, clocking up 95 episodes.