Sam Akos. Well, he was out, but he was black, a huge Ghanaian. Wearing white face under his ski mask would be an interesting disguise. It seemed wrong. Gillard looked through Akos’ record. He was six four. Car coat man was perhaps six one, max.

Skin tones and body shape seemed to rule out another half-dozen drug dealers, organised crime operatives and general lowlifes. Colin Ellis, a double murderer who was definitely out on licence, looked promising. He was the right build, and he was certainly physically capable. But he had spent the entire Internet revolution inside, was probably a bit too old, and wasn’t the brightest spark in the first place. Gillard couldn’t imagine Ellis working out how to send a delayed text message. Posting a letter was probably his limit, so long as someone wrote it for him.

That left Rodney Wells, who was an international fugitive last seen on the Costa del Crime. Wells was certainly smart, and elusive. But why would he come back to Britain? Then he considered those who didn’t have a criminal record. There were a couple of travellers who had made threats against Gillard’s ‘children’ a few years ago after he had arrested them for stealing quad bikes. The two men were unaware that the detective was childless when they claimed to know where his kids went to school.

All in all, it just didn’t seem a very promising crop of possibilities. So perhaps it was someone he didn’t know.

Detective Inspector John Perry had needed something to keep his mind off the state of his marriage. So he tracked down the man in charge of the original Jane Morris case. Retired Detective Superintendent Wilfred Mottram lived pretty close to the scene of the abduction in South London, just half a mile south in one of the big double-fronted Victorian houses on Bedford Hill, near Tooting Bec Common. The man who answered the door was a Ronnie Kray lookalike, in his late sixties, a sizeable slab of a bloke, with tinted glasses and a big pockmarked face. Mottram led Perry down a hallway past stacks of cardboard boxes through to the conservatory at the back of the house. There were more boxes here, with Samsung and lesser-known electronic brands emblazoned over them.

Seeing Perry’s gaze, Mottram volunteered: ‘It’s my post-retirement business. I buy in mobiles in bulk, and sell them on eBay and other online marketplaces.’ They chatted about the rise of the delivery economy, until the detective inspector decided they’d had enough small talk to lubricate the more serious questions.

‘So as I said on the phone, I’ve come to ask you about the Jane Morris case.’

Mottram remembered the case very well. Over tea and jaffa cakes he relayed to the younger man the difficulties that they’d had.

‘The governor wanted a quick result. We must’ve interviewed five hundred West Indians looking for the guy with the T-shirt. That created a lot of resentment in the local community, which even then had quite a high ethnic population.’