The bomber dived through a crumbling stone arch, running flat out, the device in his hand.

Then suddenly he was cartwheeling through the air with a loud grunt of pain and surprise as the moped coming the other way knocked him off his feet.

Ben came skidding out of the archway just in time to see the bomber go sprawling across the narrow street in a tangle of arms and legs. The scooter crashed down on its side and slithered in a shower of sparks. The rider tumbled and rolled. The black detonation device went bouncing across the paving stones.

There was blood on the bomber’s face. His teeth were bared in pain and concentration as he went crawling after the fallen device. Ben watched in horror from ten yards away as his trembling hand reached out for the tiny keypad. Then his fingers were closing around the device, dragging it towards him.

Ben dived at him and punched him hard in the head. He punched him again. The man’s head lolled, spitting blood. Ben grabbed for his fingers, wrestling the thing out of his grasp.

There was a sharp yell from behind. Ben turned. A young cop was standing three yards away, panting hard, pistol wavering, sweat on his face. He motioned with the gun. Ben could see in his eyes that he was scared. Scared, but serious. He screamed a command in Hebrew.

Ben raised his hands, slowly rising to his feet.

The young cop flicked the gun towards the bomber.

But the bomber just smiled. He sat up in the dust and cocked his thumb over the SEND key.

The sequence was complete. One key-stroke and the world was going to change irrevocably.

Ben moved faster than he’d ever moved before. His elbow hit the young cop’s face at the same time that he was already grabbing for the pistol. The shot was completely instinctive. He didn’t aim.

The bullet hit the bomber’s hand in a mist of red, blowing off half his fingers. The shattered detonator dropped to the ground.

The bomber kneeled there, nursing his damaged hand, staring up at Ben open-mouthed. ‘Who are you?’ he croaked.

‘Nobody,’ Ben said. Then he shot him in the head.