Well, what do you think? I mean you've seen the movie and you know the score: Michael J Fox is as watchable as ever, Christopher Lloyd is as great as ever and - with the exception of the offensive suggestion that Chuck Berry stole his genius from a middle-class white boy - it's a hugely entertaining film. But you know that it's not going to make a decent book. And indeed it doesn't.

George Gipe makes a decent enough fist of reworking the screenplay (by Robert Zemeckis and Bob Gale of 1941 infamy), but there's really no point. He shouldn't have bothered.