‘The interior of the car was doused with petrol. There’s what looks like the remains of a plastic fuel container on the back seat. Fairly consistent burn throughout.’

‘Someone did a good job?’

‘Yeah, pretty thorough, I’d say.’ He held up the bag. ‘We found what’s left of his wallet in his pocket.’

‘And those?’ Joe asked, gesturing to some keys in the other bag.

‘In the glove compartment. They’re from a BMW. Fire-resistant key fobs. German engineering, eh!’

Joe nodded. ‘Vorsprung durch… Or is that Audi? Anyway, what else?’

‘Some bags under the seat. One of ’em looks like cannabis. But, y’know, what with the heat and everything, difficult to say for sure. Imagine the smell in there, though! At least he’ll have died happy.’

So much for respecting the dead. The SOCO moved off as a photographer leant into the opened door and started snapping.

Joe moved out of the way to let him get on with it. What if that was Sam? he asked himself. Charred to death, his motor loaded with drugs. What if Jackie had been an addict, and Joe hadn’t been around? What was it Jane Shaw had said? ‘Mother was a junkie, dad was nowhere.’ Now this. Black on black. It shouldn’t matter. But it does.

‘Anything in particular you want me to get, guv?’ the photographer asked.

Joe looked around, still thinking about Sam.

‘You done all the usual? Inside the car? Plenty of wide shots of the whole place, different angles, from all corners of the car park?’

‘I reckon.’

‘OK. Can you do some 360s from here, looking out from the car? Let’s try to see what the quickest way out would be.’

‘Will do.’

It was always a good idea to get someone to double up on your thinking. Joe took a step back and watched the photographer work. He felt the low branch of a tree brushing his shoulder, and turned. Quick way out? The trees were so close. This was where you’d go, straight under cover. The car had been parked here for a reason, next to the trees.

The photographer seemed to be thinking exactly the same. He walked past Joe and made his way between the branches.

‘This is where I’d go,’ he said, as Joe followed him. ‘If I didn’t have any wheels.’

The two of them went through the trees. A matter of a few yards, no more than that. No point looking for footprints. The ground was thick with leaves and wispy undergrowth. After the trees was a wall, the outer limit of the park. Three feet high, and on the other side was a narrow lane, the tarmac old and scarred, no street lighting in sight.

He leant on the wall and took out his phone. Eleven-thirty in the morning? Sam was probably in lectures. He dialled anyway.

Three rings and it clicked to voicemail.