"That was the scene in California's Mojave Desert five years ago - our historic first view of the Newcomers' ship. Theirs was a slave ship, carrying a quarter million beings bred to adapt and labour in any environment. But they'd washed ashore on Earth, with no way to get back to where they came from. And in the last five years, the Newcomers have become the latest addition to the population of Los Angeles... "

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.