‘They swapped vehicles?’ Nick said. ‘Into a car. So where is the van?’

‘We don’t know. Not at the site, though.’

‘So Josie might still be in the van?’

‘I don’t think so. These people can control their routes and locations to avoid CCTV, but not here, not around your house. It’s the danger zone. The van could be compromised. It’s probably why they swapped it so quickly. I expect to find that van a smouldering wreck some time soon. But here, look, we think the car scraped along the side of the garage doorframe as it left. We found green paint.’

‘So, the contact and exchange principle,’ Nick said. ‘So you can do a solvent test to match it when you find the car.’

A child doing applied mathematics wouldn’t have got such a surprised look. ‘How did you know that?’

‘You police like to let TV companies film your investigations. You give up all your tricks—’

‘Just tell us what you know,’ Anna said, visibly upset and clearly impatient.

‘I’m sorry, dear, of course, yes.’ She hit the keyboard, pulling up a still from a high CCTV camera covering a garage forecourt. A car barely visible on a portion of the main road at the top of the screen had been circled in electronic ink. ‘A631, heading south. We reckon this is the car. There’s another camera later, further into Brinsworth, but we don’t see the car on that camera. It might have stopped somewhere between.’

‘Josie is being held in Brinsworth?’ Anna said. ‘That’s only a few miles away.’

‘It could have turned off a side road. Or they could have swapped vehicles. They swapped from a van to this green Volkswagen Passat, so maybe they swapped again. Please, let’s not assume anything until we know.’

‘A Passat? So you know which kind of car. Are you tracing Passats?’

‘Of course, yes. Yes. Now take a peek at these.’

Anna grabbed Miller’s wrist, preventing her from working the keyboard. ‘But have you searched Brinsworth for this car? There can’t be many green Passats there.’

‘There are none seen so far, dear. Sorry. We’ve driven the area. We’re still looking, but it takes time. Now have a look here. Do you recognise anyone?’

Four photographs. Four police mugshots. Three men and one woman, each of whom was registered as owning a Volkswagen Passat, and a criminal record.

‘You said the first caller was a woman pretending to be a man, for whatever reason,’ Anna said, jabbing the mugshot of the sole female. ‘Is it her? Have you arrested her?’

‘They would have already said, wouldn’t they?’ Nick said. A little too harshly.