The Arab in the cubicle beside me said something in Arabic, which I didn’t understand. I heard the splintering sound of a wooden door parting company with its hinges, followed by a scream of terror, which then turned to a scream of pain, a terrible scream. Suddenly, it stopped completely and was replaced by a weird gurgling sound. I struggled with one hand to pull up my trousers and with the other to yank my Beretta out of its shoulder holster, as I heard the fast patter of sandals retreating from the room.

I dashed out of my cubicle, struggling with my zip, and looked into Ahmed’s cubicle. The door had been kicked off its hinges, and was suspended by its lock. Seated on the lavatory was just a volcano of blood. Ahmed’s head had been almost completely severed, and hung at a strange angle to his neck, from which blood was erupting and running down his jellaba. His arms were outstretched and rigid. The only movement of his body was a macabre twitch in his left cheek.

I gagged twice and had to swallow hard to prevent myself from throwing up. I gaped in horror, and as I gaped, a fury grew inside me. I turned away. If any man had ever wanted to convince me that he had been telling the truth, he couldn’t have done a better job than this.

The fury turned to a rage, a rage against all the terrorist bastards in London, in my town, in my world, for their ever-increasing gross outrages. I was going to get the bastards that had done this particular outrage, and I was going to teach them a lesson they would never forget. I hurtled out into the corridor. There was no one to be seen. I sprinted to the end of the corridor and dived down the stairs. As I hit the foyer, I looked in every direction, and saw a side door down one end swinging shut. I sprinted towards and through that door, just in time to see an Arab scramble into the back of a dirty grey Fiat, which drove off before he had time to close the door. I looked desperately around for a vehicle to commandeer. Almost on top of me was a taxi with its ‘For Hire’ sign illuminated. I scrambled into the back.

‘Follow that grey Fiat.’

‘You what?’

‘Follow that Fiat!’

‘What is this? The movies?’

‘No – it’s a ten quid tip if you do what I say.’

He did. The Fiat had slowed right down in a bottleneck at a roundabout and the cab got onto its tail.

‘Stay right behind it, and don’t lose it.’

‘Orl try.’