The first police at the scene were two officers from Chelsea police station in Lucan Place, who arrived at the same time as the ambulance. While one heard a confusing mixture of contradictory accounts from bystanders, staring with hands over their mouths, or talking into their mobile phones, the other spoke to the driver of the number 22 double-decker bus that was pulled into the kerb. White-faced and jerky in his gestures, the driver was in absolutely no doubt about what had happened.

‘After the Sloane Square stop the road ahead was clear. I crossed Cadogan Gate and noticed this bloke up ahead turn and see me coming, then start running, and I thought, you’d better get a move on if you want to catch us at Pont Street, mate.’

‘How fast were you going?’

‘Twenty, twenty-five, no more, God’s my witness.’

‘Go on.’

‘This runner dodged around the people on the footpath, then as I got closer he charged straight into this old couple. I saw one of them, the bloke, go flying, and I thought, you stupid bugger, look what you’ve done. Then…’ The driver hesitated and stared for a moment at the policeman’s chest, as if he could see a film unreeling in front of him there on the black protective vest. ‘Then the runner grabbed the other one, the woman, and lifted her up in his arms, like she was a baby, and spun her around and threw her in front of my bus.’

‘Hang on,’ the officer began, but the driver had buckled and was being sick over his boots.

TWO

‘N ancy Haynes, American tourist, age seventy.’ The constable handed the passport to DI Kathy Kolla. Around them, the lobby of the casualty department was crowded, staff hurrying around members of the public seated in glum ranks.