He did a quarter turn before impact, his back smashing into the point where the upper and lower sash met. Time and damp conditions had long since weakened the wood, and it crumbled, the two halves of the window frame bursting outwards like they were made from papier-mâché. The noise was deafeningly loud after the relative silence that had preceded it, but Owen Carter heard nothing except the wind whistling in his own ears, and soon not even that.

James Bolton looked out through the splintered frame, down to the road below. Carter had landed with arms and legs splayed out, like a child making snow angels in winter.

‘I did promise you would leave in one piece,’ Bolton muttered to the empty room. He saw movement off to his left down below, figures running towards the broken lump of flesh and bone that used to be Owen Carter.

‘Message delivered. Job well done, Mr Carter.’

Simmons almost missed it. After nearly fifteen minutes of inactivity, she stood up straight behind the wall and rotated her neck in an effort to banish the stiffness. Moments after she resumed her position, she saw the window burst outwards a split second before the crash reached her ears. She watched, helpless and horrified, saw the arms doing a frantic front crawl in mid-air, looking for purchase but finding none. She heard the sickening thump even from that distance, then silence.

Gibson’s voice roared in her ear and broke the spell. ‘Go, go, go!’ He raced past her and out into the street. She fell in behind him, her fitness letting her keep pace despite her shorter stride. A flash of movement caught her eye and she glanced upwards just in time to see a shape in the window before it pulled back. It happened so fast she couldn’t be sure, but from the size of the shadow, it had to be Bolton.

Gibson reached the door ahead of her and pulled out his ASP telescopic baton. Simmons followed suit. He pointed for her to spread right when they went in and he would do the opposite. She nodded agreement, fighting to control her breath after the sprint, but revelling in the adrenaline rush that made her heart feel like it was trying to leap out of her chest. She glanced back at the corner they had sprinted from. No sign of the officers from the other units. They had been sat in their vehicles and might not have even heard Gibson’s shout. Best case, they were a good twenty seconds behind them. Gibson held three fingers up and mouthed the countdown.

Three … two … one …