One of the early-1990s most fondly-remembered series, Quantum Leap was the latest in a long line of time travel shows. In this case Dr Sam Beckett (Scott Bakula) travelled back in time, displacing someone else whose mind (and body, according to later episodes) would be transported to the late-1990s where the Quantum Leap project was based. People in the past would still see the displaced person.

Unsurprisingly, Sam was unable to return home and kept leaping from place to place, helping people and changing time in a minor way as he went along. His only help on his travels was Al Calavicci (Dean Stockwell), an ex-Navy Admiral and Vietnam POW, in the form of a hologram who only Sam could see and hear, and who had a penchant for cigars and extremely loud shirts.

The series eventually ran for five seasons before being cancelled, with the final episode of the series, Mirror Image, proving controversial as Sam arrived in a mysterious bar on the day of his birth. By the end he realised that he could return home, but only if he really wanted to, and he decided on one further leap before doing so — returning to the scene of the episode M.I.A. and reuniting Al with his first wife, Beth.

The series ended with a caption explaining that Sam never returned home...