‘I’ve put a few people away in my time.’

Otara stroked his neat beard. ‘Yes, but I’m particularly intrigued by your wife’s ex-boyfriend Gary Harrison. DI Claire Mulholland thinks he is possibly the best candidate, although it’s unclear whether he would have the technical skills we have seen exhibited. We have two research specialists trying to trace him, going back through everything we know from him in his army days and when he was a chef.’

‘If it is him, he might kill Sam,’ Gillard said. ‘It won’t be about money, it’s about getting even with me.’ He described his own attempts to trace Harrison’s whereabouts.

‘I agree. Having seen the messages, this is clearly not a conventional kidnap case. That makes it difficult because there are no demands, no cash we can offer and precious little to negotiate about.’

‘What is your strategy then?’ Gillard said.

‘Trace the car. Our perpetrator has been moving around a lot, transporting corpses and who knows what else. That is the weakest link, and unlike with phones it’s more difficult for him to give us a false signal.’

Gillard nodded. It was a logical conclusion.

‘So, as he seems to be pretty good at staying off main roads, we are ramping up a surveillance operation with twenty mobile ANPR cameras concealed in parked vehicles on various back roads between Woking and Lacey Dutton on the western edge, and right across to Croydon and Caterham in the east. We are putting together an analysis of all the cell site data we have accumulated, not only on Beatrice Ulbricht’s phone, but on your wife’s too, or what we’ve been able to recover from it. We are monitoring her social media accounts to see if anything pops up there.’

‘That’s all very well,’ Gillard said. ‘But I think our suspect has gone to ground. He’s done all the driving, all the texting, and all the setting up he needs. He’s watching to see if we can find him. And my gut feeling is that he has eyes and ears in the police.’

With Mount Browne like a disturbed ants’ nest, and overrun with the bomb disposal people, NCA officers and miscellaneous spooks, DI John Perry took Rainy Macintosh to a small conference room, where they could shut out the mayhem and he could give his full attention to what she’d learned in the Jane Morris case.

‘Boss, after yuz alerted me to the chance that Jane Morris had given birth, I checked through one of those ancestry websites. You might not know this but you can get school attendance records from it as well as births, marriages and deaths. Because of the unusually common name, it took me a while to work out which South London secondary school wee Janey had been to. Then I realised I was being stupid, because one of the photographs released at the time showed her in school uniform. What I discovered was that she had not attended at all in the six months prior to her death.’