Written by Eric Saward, starring Colin Baker as the sixth Doctor, Nicola Bryant as Peri.

Recorded in 1985, during the television show's hiatus, this radio play was presented as part of a children's magazine-style program called Pirate Radio Four. Although six episodes, it only has a total running time of one hour (with each episode being ten minutes). It's interesting to note that the cast includes Valentine Dyall, best know to Who fans as the Black Guardian. Sadly, 'Slipback' was his final performance as he died shortly after.

Quite an interesting if unremarkable story, penned by Dr Who script editor of the time, Eric Saward, that provides a new twist on the Big Bang theory. Dyall's character, Captain Slarn is a highlight. He's obese, repulsive, prone to contagious diseases when made angry, and very amusing. The computer with the split personality is also rather interesting.

The cliff-hangers are a little over-the-top, and the inclusion of the Time Lords rather contrived. Despite this, it's all rather entertaining, with a cute ending. Worth a listen.