The red backpack was exactly the same as the one in the CCTV snatch shot on the day he bought hydrogen peroxide in a chemist’s wholesale warehouse.

He was wearing that red backpack when he wheeled out the 440 litres of hair bleach to the cash desk. Wearing it when he counted out the £550 in fifty-pound notes. Wearing it when he unloaded his van at the lock-up garage where we had put our cameras.

You couldn’t miss that red backpack. It looked like the kind of bag you would use to climb Everest. Big and bright – safety red, they called that colour.

But his face was not the same. That threw me. It was meant to. The face had been pumped full of something. He was planning to go to his death with the face of another man.

But I could see it now.

There was no doubt.

‘That’s him,’ I said. ‘Contact. He’s had something done. I don’t know. Some work to his face. But that’s him. Contact. Confirming visual identification. Contact.’

‘Sniper 1 in range,’ said a voice, and across the street I saw the shooters for the first time, three figures moving on the rooftops above a shabby strip of shops and restaurants, their weapons winking in the sunlight. Police marksmen, settling into position.

Our last resort, if it all went wrong. And it was already starting to go wrong.

‘Sniper 2 in range. But I don’t have a trigger. No clear shot. It’s crowded down there.’

The man with the red backpack had paused on the far side of the road, waiting for the lights to change. Traffic thundered by, and in the gaps there were flashes of safety red. I touched my earpiece. Suddenly nobody was talking to me any more.

‘That’s our boy,’ I said. ‘Positive ID. Contact. Contact. Over.’

The lights changed and the traffic reluctantly stopped. The commuters began to shuffle across the road. The man with the red backpack went with them.

I spoke slowly and clearly: ‘This is Delta 1 confirming contact. The target is about to enter the grab zone. Do you copy me? Over.’

And nothing but the white noise in response.

And then: ‘Possible. Checking. Stand by.’

I shook my head and was about to speak again when the calm voice of DCS Swire said, ‘It’s a negative, Wolfe. That’s not him. Negative. Cancel.’

And then the voice of the surveillance officer: ‘Negative. Cancel. Stand down all stations.’

The lights changed again.

The man with the red backpack had crossed the road.

He was heading for the railway station.

‘Do you expect him to wear a burka?’ I said. ‘That’s Bravo 1. That’s the target. That’s our boy. His face—’

‘We do not have visual confirmation,’ the surveillance officer said. ‘We do not have positive ID, Delta 1.’