Let me start by saying the end isn’t relevant

Now that we are halfway through, Rob Long wants us to take a minute here

Tom Cruise and Jeremy Renner grapple on the Burj Khalifa, in Mission:Impossible - Ghost Protocol

There’s an old story – the kind of story journalists call “too good to check” – about the filming of the classic detective movie The Big Sleep.

The movie – starring Humphrey Bogart as the iconic cold-hearted detective Philip Marlowe, and Lauren Bacall as his mysterious femme fatale – is a dark, moody picture filled with rain and cigarette smoke and crackling dialogue between the two stars, but it’s also almost impossible to figure out what’s actually going on. Who killed whom, and why, and when, are questions pushed to the side to make room for lots of smouldering looks from Bacall and tough-guy wisecracks from Bogart.

It’s a great picture, of course – a true classic – but it’s fair to say that it doesn’t make a great deal of sense. Then as now, most Hollywood pictures are written by a series of screenwriters, all writing and rewriting each other until they’re told to stop.

The Big Sleep has three credited screenwriters and when you toss a lot of writing talent at a story what you get is some extraordinary dialogue but not a lot of plot-line clarity.

The movie is a baffling series of twists and elliptical conversations, and the legend goes that midway through the filming Bogart asked the director, the great Howard Hawks, to explain how the story actually worked. If this guy killed that guy, Bogart asked, then who killed the other guy?

Hawks thought for a moment, then shrugged. He had no idea. But he knew someone who would – the author of the original novel and the creator of the character of Philip Marlowe. So he and Bogart called up author Raymond Chandler and put the question to him: if this guy killed that guy, then who killed the other guy?

There was a silence on the line.

“I have no idea,” the author of the book is reported as saying. “But does it really matter?”

Of course it didn’t. The point of the movie wasn’t to solve a mystery, it was to get two romantic movie stars on screen together, to show off what we call their “chemistry”, and as anyone who has seen The Big Sleep can attest, Bogart and Bacall had lots of chemistry.

Some pictures, though, are in a slightly different position. Last week, in the middle of the production of the fifth instalment of the Tom Cruise blockbuster movie series, Mission: Impossible, the studio decided to halt filming for a week so that the producers – who include Cruise – and the director can figure out how to end it.

At some point, I suppose – much like Bogart and Hawks years ago on the set of The Big Sleep – Tom Cruise and the director sat down to read the rest of the script of the movie they were currently shooting and both looked up at the same time and asked each other the same question: “What’s going on here?” And then: “We’d better take a moment and figure this thing out.”

It sounds crazy, I know. What on Earth would possess a giant movie studio to start production on a hugely expensive picture without knowing in advance how the thing was supposed to end? Well, the first thing to bear in mind is that the last Mission: Impossible movie, the fourth instalment, earned almost US$650 million worldwide, so as far as the executives at the studio were concerned, the most important thing in the world – more than their health and the health of their families – was to get Mission: Impossible 5 up and rolling.

“Just get started,” is an important rule in Hollywood – and in a lot of other businesses, too. (It’s also useful in life, I’ve found.) The forces of inertia, fear of failure, endless thinking and rethinking – these are all the enemies of decisive forward action.

A studio that keeps reworking a script until it’s perfect may find that it has lost out on the perfect cast or the right director; or worse, that the audience taste has moved on; or worst of all, that another studio has released a picture with the same essential storyline. When this much money is at stake, the rule is: Just get started.

“Fix it later” is another important rule. If the script needs work you can rewrite it on the fly. If the picture isn’t quite right you can adjust it during the post-production process. Knowing that you can “fix it later” is the chief reason you can “just get started”.

So last week they shut everything down, at enormous cost, and are right now holed up somewhere – Tom Cruise, the director and a writer – trying to figure out how to end a movie they’re halfway through filming.

The movie opens this summer – its official release date is July 31 – so there are early advertisements being produced and trailers being cut.

Wherever Tom Cruise and his team are right this minute – probably in some expensive hotel suite, staring at a large computer screen with the word “Ending?” written on it – the pressure must be immense. Think of that later this summer when you go to see the film.

Just get started. Fix it later. These are words of wisdom for any business, and any life, too. They seem to fit every human endeavour. Except, I’m told, marriage.

Rob Long is a writer and producer based in Hollywood

On Twitter: @rcbl