And then there was a sudden searing heat on the side of his face, as if he’d stepped too close to a bonfire. At the same time came the tinkling of glass on concrete and wailing screams. He was shoved to one side as bodies flung themselves towards him. There were more cries – a baby yelling, a man shouting a name.

Asad looked around wildly. Behind him, about thirty metres away, he could see the lick of a yellow flame and a drift of dirty smoke over the heads of the crowd.

Mirza was beside him, eyes wide open.

‘Out of here,’ said Mirza. ‘Omar. Now.’

Asad didn’t argue. The instinct to get away was overwhelming. But the same instinct had run through the crowd and bodies pushed and jostled from all around. It was a struggle to move now, he was being pressed on all sides as panic swept through the protests, his body bobbing around like a buoy in a turbulent sea.

He felt an elbow in his face and he pushed back sharply and looked round into the pale face of a woman, aged in her seventies or eighties. ‘I’m sorry,’ he mouthed, but she was swept away further to his left. Panic grew in his stomach. And the panic, terrifying, paralysing panic, was spreading through the crowd.

There was another pop, a smashing of glass and a second wall of heat. Asad glanced up – more flames, this time on the other side of the street.

He looked around – he and Mirza were being sucked by the torrent towards Trafalgar Square.

‘In here, Tanvir,’ yelled Asad and he grabbed Mirza, sending him toward a side passage. The entrance to the passage was obscured by scaffolding and most of the fleeing crowd swept past oblivious. Asad stood in the entrance and peered back into the street as people pushed past them down the passageway. Police in yellow vests were pushing through the crowds, trying to hold some back, steering others away.

Then the screams got louder. And this time, the crowds began to run. Asad heard a repeated cracking sound, like a firework had been thrown into the street.

‘That’s a gun,’ said Mirza. ‘The police are shooting at the crowd.’ The screams got louder. Sirens started to go off.

‘Let’s get out of here,’ said Asad, and they ran down the passageway away from the chaos and into the relative tranquillity of St James’s Park.

#

Inside the entrance hall to Charing Cross Tube station, Zahra heard the muffled bang of the petrol bomb. Maryam turned to her. ‘What was that? A firework?’

Zahra shook her head dumbly. Her mind wasn’t working. She had just one thought. Not again, this couldn’t be happening again. Not again. Around her, people stopped and turned to the daylight. The crowd was eerily quiet. And then, outside, the sound of gunfire, echoing against the concrete and stone. The noise was unmistakable, as was the rise in volume of shouting outside. Not again.