At last, Marty's Uncle "Jailbird" Joey makes parole and now he's coming home to visit his favourite nephew. But is Marty happy about this? Well, not exactly. In fact, Marty's not even sure why Joey went to prison in the first place back in 1972. So when Marty starts asking questions, he's shocked to learn that the mystery somehow involves Doc Brown. Fasten your seat belt and get ready for another time travel adventure, including the return of Professor Marcus Irving and an introductory tale that takes us to the amazingly futuristic world of 2017.