‘Sulaiman.’ A yell came from his right. His brother was next to him. ‘Thank God you’re okay.’ Then he looked at his shirt. ‘You hurt?’

‘I’m okay – I got a scratch from something, but it’s okay. Listen, can you take the boy for a moment?’

‘Of course.’ His brother scooped him into his arms and kissed the child on the forehead. ‘Stay close though – it’s a miracle I found you. Did you see what happened? Did you hear the gunfire?’

Khan shook his head. The people around them were quiet. There was no shouting, no screaming. Just a flow of bodies moving relentlessly onward.

They were to one side of Wembley Way now. Ahead, a young black man was stood watching their faces, facing the wrong way. Something metal – it looked like a camera and tripod – was hanging down from his right hand.

Khan was closer now, no more than ten metres from the man. Their eyes met and Khan knew immediately that something was badly wrong. The man didn’t look scared like the faces around him, but impassive, uncaring, unbothered.

The man glanced down at his right arm and Khan followed his gaze. It took a moment for his brain to register what his eyes were seeing. The metal object was a gun – olive green, functional and incongruous in this crowd. Khan barked at his brother, ‘Get away. Now,’ before turning back to the man. Their eyes met again.

Afterwards, Khan couldn’t explain to the police, his brother or his wife why he behaved like he did. And even as he started forward to the man, he knew the sane response was to run, to hide, to shout. But instead, part of his brain told him to challenge the man.

‘Put it down,’ he yelled. ‘You. Put it down.’

The man was expressionless. He stared blankly as Khan advanced towards him, now just a few feet away. And then he raised the rifle butt in his left hand and swung it up sharply into Khan’s cheek. Khan staggered back, blood dribbling onto his shirt from the graze. The man lifted the rifle again and jabbed the butt into Khan’s chest. With an exhalation of breath, Khan collapsed.

#

The crowd parted around Asad, moving back, creating a circle of space in the packed avenue. The Asian man was still lying on the floor, clutching at his chest.

And in that moment, as he stood over the writhing body, the boy Jack’s face came back into Asad’s head. And Asad knew he could not go on with this. The tsunami he had been riding wasn’t unstoppable. He had a choice. And his choice was to walk away now.

He turned, clutching the rifle in his arms like an infant.

‘Drop the bag.’

The shout came from behind. A woman police officer was pointing a rifle at him. Another man in uniform, but with no gun, was stood next to her.

‘I said, drop the bag.’ The woman was Northern Irish. She stared at him with expressionless eyes. Asad could sense the crowd moving away from him. From the corner of his eye, he saw men and women in fluorescent jackets pushing and diverting the crowd, creating an arena for him and these two police officers.