"Quantum Leap" is a science fiction television series that aired from 1989 to 1993. The show follows Dr. Sam Beckett, a physicist who invents a time-travel experiment called Quantum Leap. When the experiment goes wrong, he finds himself "leaping" into the bodies of people at different points in time, where he must correct historical mistakes before moving on to the next leap. Each episode features Sam, portrayed by Scott Bakula, accompanied by his holographic friend, Al Calavicci, played by Dean Stockwell. Together, they navigate various challenges and moral dilemmas, exploring themes of redemption and the impact of individual choices on history.