Rather than a train of thought, I wonder if the creative process involves a train crash. Two unrelated ideas which, when they collide, produce a bang, lots of sparks and a pile of new possiblities. Let's see.

1. I had a train of thought involving multi-storey car parks. We arrived at one at Gatwick Airport and they're always intimidating. Big concrete structures with a number of pillars, behind which a person could hide, and some deep shadow. If you're not careful you can lose your car, or your passengers. Whereas the one at Gatwick was full of cars and people, there have been times when we have returned from a concert in Brighton and found the car park deserted and dark. For a writer or film maker a multi-storey car park is an ideal location for a murder.

2. Another train of thought concerns the migrants who are camping in Channel ports and trying to cross to Britain. Once when we arrived at Dieppe, we saw a young man being bundled out of a white van and handcuffed by Customs officers. I have a good deal of sympathy for those who are trying to escape war and persecution and build a better life in Europe. Some have been killed trying to cross the Channel, while others have resorted to violence. There must be material here for stories.

3. So, what happens if we write about a young migrant – let's call him Abdullah. He climbs out of a van late at night and finds himself in a multi-storey car park. As he stands near the van, wondering where to go, he witnesses a murder. What happens next?

The Witness

Abdullah opened the door of the van and stepped out. Where was he? The place was almost completely dark, with a few lights in corners. Here and there cars were parked but nobody stirred. For a few minutes, he stood and allowed a sense of relief grow in him, as if he was sitting by a warm fire. At last he had arrived safely in England. He'd heard of people who'd died attempting the crossing, so getting here was a triumph. Next, he needed to find out where he was and scrounge something to eat. He guessed the lights might indicate doors and started heading towards one.

The sound of an engine approaching made him stop, then retreat into the shadow of a pillar. A silver coloured car drove up a slope and parked, the headlights were turned off and a man stepped out. He stood, leaning against the car and smoking a cigarette, as if he was waiting for something. Abdullah crouched in the shadow and watched. He had spent months waiting in Calais for a chance to cross the Channel and wasn't going to allow a rash move to trap him now.

The door towards which he had been heading opened and a second man appeared and walked towards the car. The two men stood talking, but the light was so poor Abdullah had difficulty making out their features. The driver was tall, stout and wore a coat and a hat, whilst the second man was smaller and wore an anorak. The smaller man's voice rose to a shout and he gestured at the bigger man, who stood still, then there was the flash of something that might have been a knife, a cry, and the small man collapsed in a heap on the ground. The big man stepped into the car and drove off, the car's headlights illuminating a body.

As soon as the car disappeared down the slope, Abdullah crept out of his hiding place and approached the body. The man's eyes were still open but he lay in a pool of blood. Abdullah had seen death often enough to know the man was dead. The sight shocked him. His homeland of Syria was a war zone but England was supposed to be a peaceful country, where people obeyed the law, yet as soon as he arrived here he witnessed a murder. In an instant, Abdullah knew he had to get out of this place. There was nothing he could do about the murder. He was an immigrant who'd crossed into England illegally and, if anyone saw him close to a dead body, they would think the worst.

Abdullah looked round, to reassure himself there was no-one watching, then he ran for the exit. He rushed down the concrete stairs and out into the street. Under a street light, a car stood, with the word Police on the side. Abdullah knew that word from the camp at Calais and knew it meant trouble for him. He turned and ran in the opposite direction but was aware of two burly policemen pounding the pavement behind him. In a moment, he was seized from behind and brought to a halt.

“Now, what have you been up to?” asked one of the policemen.

You can decide what happens next!