Craig Shaw had the mill-town run sewn up. That’s how it looked, a regular sales route, which implied regular customers, or a small-scale supply chain. This was a nice lead, a bit of potential, better than investigating some pusher working the streets. Something didn’t fit, though. Craig was living with his mum, borrowing her car and her phone. Nah. If you’re picking up a week’s gear every Monday, same place, somebody trusts you. It’s steady trade. You’re higher up the ladder. You wouldn’t be borrowing your mum’s phone. And what does a drug dealer do as soon as he has any cash? Buys a decent motor. He doesn’t drive around in his mum’s old Corolla. Yet no vehicle had ever been registered in Craig Shaw’s name on the DVLA database.

He checked his watch. He’d already phoned Alex, head of Digital Forensics. Ring him again? No, best not rush him. Don’t make it sound like a favour. Not for a case like this. If it even was a case.

He looked at the information he already had. Jane Shaw’s police record was limited to a few cautions for possession, the last one fifteen years ago. Nothing since then. He’d ordered her DWP file, but that wouldn’t be available until the morning. He rifled through the remaining papers. The rest of her story checked out. She had been at that address for nearly six years, and the car was legally hers.

Think: her son went missing for a handful of hours and she rang the police? He repeated it to himself. She rang the police. Because Craig hadn’t paid his rent, in kind or otherwise? Bullshit. There was something she wasn’t telling him.

Alex Ambler walked into the operations room. He was lanky and unshaven, and had the air of someone who’d just dragged himself away from a very long game of Dungeons and Dragons. Yet despite the bed-head and a permanent yawn, Dr Ambler was the best-qualified person in Leeds Police HQ. After a PhD in computing, he’d got bored with university life and applied for a job in Forensic IT. A few years later he was a demi-god at Elland Road. A number of high-profile cases had gone to trial thanks to his expert intervention, and he’d even begun to publish articles in academic journals on cybercrime. He may have been a support worker, but Alex outshone the lot of ’em in CID.

He was wearing faded black jeans and a Whitesnake T-shirt with holes in it. The effect was a touch rebellious, bordering disrespectful. But no one dared to mention it. They all needed Alex, right to the top. They needed him more than they needed the Chief Superintendent, who in fact no one needed at all.

‘OK,’ he said, ‘I’m here.’

There was no small talk with the King of Tech.