May 21, 1979: Sam leaps into Ray Hutton, the understudy for the role of Cervantes just seconds before curtain time. His mission: prevent the drunken star from falling and seriously injuring himself during a benefit performance of 'Man of La Mancha'. Sam isn't helped by the presence of his former piano teacher, on whom he once had a crush, and who now appears to have caught the star's eye as well.
Theorizing that one could time travel within his own lifetime, Dr. Sam Beckett stepped into the Quantum Leap accelerator and vanished... He woke to find himself trapped in the past, facing mirror images that were not his own and driven by an unknown force to change history for the better. His only guide on this journey is Al, an observer from his own time, who appears in the form of a hologram that only Sam can see and hear. And so Dr. Beckett finds himself leaping from life to life, striving to put right what once went wrong and hoping each time that his next leap will be the leap home.