GREAT SCOTT, MARTY! A time-travelling fridge!

As Back to the Future turns 40 with a cinematic re-release, its creator Bob Gale reveals why Michael J. Fox nearly wasn't Mart McFly, the Delorean could have been something quite different... and the iconic Johnny B Goode sequence only just made it on screen

- Tom Fordy

IT SEEMS fitting that Back to the Future - the classic Eighties’ time-travel adventure about serendipitous intervention, chance meetings and changing fates - might have been very different.

In the film, which is in cinemas to mark its 40th anniversary, Marty McFly (Michael J. Fox) travels from 1985 to 1955 in a DeLorean time machine and - Great Scott! - disrupts the moment his parents were destined to meet and fall in love, which threatens to erase him from history altogether.

With the help of his scientist pal Dr Emmett “Doc” Brown (Christopher Lloyd), Marty must get his teenage parents to fall for each other then return to 1985 by harnessing the power of a history-making lightning storm. But had the timelines aligned in any other way, if just one of the decisions behind the film had played out differently, Back to the Future might have featured a time-travelling fridge powered by Coca-Cola and a chimpanzee sidekick - all details in early drafts of the script.

It could have also starred a completely different actor in the lead role. Eric Stoltz was cast and filmed for six weeks before director Robert Zemeckis fired him and turned back time - in movie production terms - to do it all again with Michael J. Fox.

And it doesn't take Doc's four-dimensional thinking to figure out that if those timelines had aligned differently, Back to the Future wouldn't have become what it ultimately did: a bolt of clock-tower-striking lightning in a bottle. It's a film that not only captures but defines a particular kind of Eighties movie magic.

If the secret to time travel was the Doc's “flux capacitor”, the secret to Back to the Future's overall brilliance was a combination of elements that became instant cultural touchstones. It's the pairing of Fox and Lloyd as Marty and the Doc. The DeLorean. The chocking chords of Huey Lewis's theme song, The Power of Love. The endlessly quotable lines (“Roads? Where we're going, we don't need roads!”).