The counter I was behind had a transparent top which gave me a chance to see out without getting my damn fool head blown off. The rope of crimson smoke had wrapped itself around Reynard’s neck and was dragging him back-up the aisle despite Crew Cut’s best efforts to pull him the other way. Even as I looked back to see if I could spot where the rope was coming from, a pulse of light raced up its length in a blaze of petrol bomb yellow, vaporising the crimson smoke as it went. It roared past me and then, as it reached Crew Cut and the struggling Reynard, the pulse slowed and dissipated the last of the smoke with a gentle pop, leaving the pair temporarily frozen – and staring in amazement.

Now, that was Nightingale.

Reynard recovered first, and with a snarl buried his teeth in Crew Cut’s neck. The man screamed and beat at Reynard’s head with his fists. Lesley hadn’t emerged from hiding yet. And she was still my priority, so stalemate suited me. Every second of status quo meant more members of the public evacuated, a tighter containment perimeter, and more chance that Nightingale was going to arrive to back me up. And if Reynard got a bit of a smacking in the meantime, I could live with that.

Unfortunately, this plan went to shit when Crew Cut fumbled inside his jacket, pulled out a compact semiautomatic pistol and bashed Reynard on the head with it.

From a policing point of view, guns are a pain. Once someone is known to be tooled up, your operational priorities are suddenly fucked up. It all becomes about managing whoever was stupid enough to pull a gun in central London and your number one priority is public safety, followed closely by officer safety and then, not so closely, by the safety of the moron with the gun. Any other operational considerations, such as arresting former colleagues, don’t enter into it.

‘Gun!’ I shouted as loud as I could.

Crew Cut whirled to point his gun in my direction in a professional, albeit one handed, firing stance. I crouched down and threw up my shield – but he didn’t fire. While he was aiming at me, Lesley launched herself out of her hiding place at him.

He was fast. Before Lesley was half-way to him he’d turned and fired – a flat loud popping sound – and then again and again. There was ripple in the air in front of Lesley’s chest and something small and fast whistled over my head.

He didn’t get in a fourth shot because Lesley swung at his wrist with what I recognised as a police issue extendable baton. There was a crack and the pistol fell out of his hand. He gasped at the pain and Lesley followed up with a sharp blow to the head then a third to his face – another crunch and a spray of blood from his mouth.