The van shot past, missing her by inches. She actually felt the warm breeze slap her face and smelled the petrol fumes. There had been two books in her hand: a French dictionary and a maths exercise book… an hour and a half’s homework for the evening ahead. As she was carried forward, her hand and arm jerked, out of control, and the books were hurled into the air, landing on the road and sliding across the tarmac as if she had deliberately thrown them away. Scarlett followed them. With the man still grabbing hold of her, she came crashing down. There was a moment of sharp pain as she hit the ground and all the skin was taken off one knee. Behind her, there was the screech of tyres, a blast of a horn and then the ominous sound of metal hitting metal. A car alarm went off. Scarlett lay still.

For what felt like a whole minute, nobody did anything. It was as if someone had taken a photograph and framed it with a sign reading ACCIDENT IN DULWICH. Then Scarlett sat up and twisted round. The man who had saved her was lying stretched out in the road and she was only aware that he was Chinese, in his twenties, with black hair, and that he was wearing jeans and a loose-fitting jacket. She looked past him. The white van had swerved round a traffic island, mounted the pavement and smashed into a car parked in front of the primary school. It was this car’s alarm that had gone off. The driver of the van was slumped over the wheel, his head covered in broken glass.

She turned back. A crowd had already formed – perhaps it had been there from the start – and people were hurrying towards her, rushing past Aidan, who seemed to be rooted to the spot. He was shaking his head as if denying that he had been to blame. There were twenty or thirty school kids, some of them already taking photographs with their mobile phones. A policeman had appeared so quickly that he could have popped out of a trapdoor in the pavement. He was the first to reach Scarlett.