I’ve spent the past six weeks locked in mortal combat with a screenplay that fought all the way. I’m proud, even if this is nowhere near as dramatic or impressive as the Kenyan farmer who recently survived three hours in the grip of a Python, a story where the distance of some four thousand miles enables me to feel strangely relieved that after being defeated, the snake in question evaded police capture and lives to squeeze another day.

One of the last parts of mine and my brother’s writing process is to do a pass through the script purely as pedants, in the hope of improving the readability. The nature of script formatting often leads you to express ideas in a slightly mangled way or to repeat things oddly. One of our most common irritations was to set a scene at Dawn and then start it by briefly describing the dawn, which means it would read…

“EXT. LONDON – DAWN

Dawn is lovely over London…”

Which is irritating because we’re basically saying the same thing twice over, once as a set up, once to point out that we want you to pay attention to it being a pretty thing.

There are of course many ways to get round this, to achieve the same aim of making the reader delight in the beauty of sunrise without having to repeat the same words.

The one place where we came mightily unstuck was the scene header for a brief sequence set on a night bus.

“INT./EXT. NIGHT BUS – NIGHT.”

To translate this for those of you who don’t spend your life in screenplays this is a title to the scene which tells the reader where and when it is taking place. This always starts with either “Interior” or “Exterior”, a tradition which I think dates back to the time when this was an important choice between filming in a studio or on location. This often strikes me as a bit redundant now that so many “interior” shots are never the less shot in the “exterior” world of reality but starting a scene without either “INT” or “EXT” does look weird so I try not to think about it.

Besides, even if the original sense of the distinction between the two has been lost, starting the scene header with this does instantly nudge the reader into a specific feeling for what is to come. Inside, be that as safety or captivity feels different to outside, whether that is freedom or exposure. But the other problem with “Interior” or “Exterior” are those times when both come into play – for instance, when your characters are inside a bus with the outside world racing past all around them.

Consequently, I am a fan of “INT./EXT.” because it means you’re in both – even if it, as a reader, it springs off the page as the ingloriously inprecise “INSIDE AND OUTSIDE”.

So our scene heading reads “INSIDE AND OUTSIDE A NIGHT BUS AT NIGHT” – simultaneously being non-committal and over specific at the same time. Of course it’s NIGHT! It wouldn’t be a NIGHT BUS if it was travelling in the day. Unlike OWLS or the even THE MOON a NIGHT BUS is something that can NEVER BE SEEN AT ANY OTHER TIME.

However, because it is also part of the format to put a general sense of time and, more importantly, lighting conditions, as the last part of the description, the only “NIGHT” I can get rid of is the one in “NIGHT BUS”. Now, despite my angry protestations that it must be night if we’re on a Night Bus, the same does not hold true in reverse. A “Bus” travelling through the “Night” is not necessarily a “Night Bus”.

For my non-London readers I’ll explain that this is not only because the script is set in the autumn and so it would be perfectly possible for a normal bus to be travelling at say, six o’clock, and for the outside world to be as pitch black as two in the morning. A Night Bus is a specific thing where, for some reason, specific rules apply.

On a Bus in London you don’t talk to people unless there is an ongoing terrorist incident. On a Night Bus it is perfectly normal to get embroiled in rambling conversation with whomsoever you happen to be sat with. On a Bus in London no one would bat an eyelid should you eat a sandwich or perhaps a burger but people would be quite freaked out and possibly angry should you tuck into a massive pizza or a filthy kebab – both of which are entirely acceptable on a Night Bus. Likewise, the strict legislation about consumption of alcohol, though still legally in place seems oddly unenforced on a Night Bus. In short, they are different beasts.

So, your honour, we had no choice but to stick with the gibberish, jargon filled line “INT./EXT. NIGHT BUS – NIGHT”.

No wonder it took us six weeks…