Gabriel watched to the end of the video, then shut down the laptop. She couldn’t blame Zahra – the girl had gone through so much and lost so much. She was usually immune to complaints about the police, yet today she felt an echo of the girl’s frustration. They could have done more. Perhaps they wouldn’t have stopped the attack, but if she’d had the resources she and Tennant had asked for, then maybe, just maybe. But this wasn’t the time for self-flagellation. She needed to turn her frustration into action.

#

Croydon, South London

Saturday evening was the quietest period of the week in the Croydon leisure centre and the only time Bob Houghton could guarantee a half hour alone in the sauna. The thought of sharing the confined space with other sweaty male bodies turned his stomach. He glanced at his watch, the only item of clothing he had on. 7.40pm. Another minute. He played listlessly with the strap. Lizzie had given him this Tissot watch for his thirtieth. Two weeks before she’d walked out. He’d been tempted to chuck it away, but he liked the chunkiness of the stainless steel. It was almost inevitably a fake, but he didn’t care.

Time up. He nudged open the glass door and padded barefoot to the changing room across the grimy floor, white towel wrapped around his waist. He had laid his clothes neatly on the bench, confident that no one would be interested in his tatty sportswear. But something was missing. Where was his Adidas vest? He loved that vest. It was vintage. Who would steal that?

Bob Houghton looked around the floor. Nothing. Only one other man was in there – a short guy with cropped black hair and a holdall. He was just leaving.

‘Excuse me – seen my vest? It’s yellow?’

‘Sorry, buddy – not seen it.’ And the man left.

That was odd. Really odd, he thought. He opened the locker and put his leather jacket over his bare chest and stomach, zipped it up tight. No one will notice, he thought. But who the hell would want to nick a sweaty shirt?

#

One hour and five minutes later, Bob Houghton’s second cousin Joe Clifton was sitting in the snug of the Clarence Arms in Hounslow, with his back to the bar and his eyes on the door. Clifton swigged from his beer bottle and placed it on the beer mat. A young couple sat down at the next table. He looked like a typical East End barrow boy – all muscles, shaved hair and swagger – but she looked quite fit though, he thought.

‘Joseph, you old poof, what can I get you?’ Jamie from work was stood by the bar. Bollocks, thought Clifton, turning round. He was waiting for someone else – the last person he wanted to see right now was Jamie, the dullest man on the planet. But he was left with no choice.

‘I’ll have another of these – cheers.’ He turned around to pick up his half-empty bottle to wave at Jamie. But the table was empty and his bottle was gone.