He nodded. ‘Reminds me a bit of this Night Stalker stuff: total jurisdictional nightmare, everyone wanting a piece of the pie.’ His lips flattened; a flash of defeat. ‘Anyway, like I say, I know a few of your people. You met Gary Perez?’ She nodded. She knew Perez but had never really talked to him. ‘He’s a good kid, Gary. Decent. Principled. What about Greg Landa?’

Landa.

She pictured him, obese and smirking, chewing on another Altoid as he’d stood there in the motel room the day before.

‘Yeah,’ she said, ‘I know Greg.’

‘I’ve worked with Greg on a couple of things.’

Jo forced a reply: ‘That’s cool.’

Callson watched her for a fraction of a second.

‘I think we can both agree that Landa’s a Grade-A asshole,’ he said.

A smile twitched at the corner of Jo’s mouth.

Callson returned it and then continued climbing the trail. ‘You need to play the game,’ he said, ‘and pick your battles. Just know that we’re not all like Greg.’

She didn’t know if the we he was referring to was men or cops – or both – but whichever one it was, she could tell Callson meant every word of what he was saying. She’d never heard a cop talk like this in her ten years at the LASD.

Ahead of them, the trail levelled out, the path bending away to the south before starting another, gentle climb, and as it did, the hillside dropped away on their right to reveal the summits and hollows of the Hollywood Hills. Jo couldn’t remember the last time she’d been up here but, whenever it was, the weather had been nothing like this. She could feel sweat running off her face, on her arms, down her back. Callson, too, was perspiring: a long, thin patch had darkened his shirt, the stain tracing the ridge of his spine, and every so often he would wipe sweat from his hairline with a finger.

A few minutes later, he pointed ahead of them, to where the path got steeper, the scrub closing in on either side, thick knots of black sage and buckwheat forming waist-high walls, and said, ‘It’s just up here.’ The path dog-legged back on itself again, into another climb, but Callson didn’t go any further; he stopped, pointing to a tiny, trampled offshoot from the main trail.

‘That was where they found him,’ Callson said.

They walked over to it, Jo trying to prevent the sweat getting into her eyes, and then took a couple of steps along the new path. It didn’t lead anywhere, just into a thick tangle of scrub, but she soon spotted crime-scene tape, tied to the branches of a tree twenty feet from her and hanging like a noose.

‘Donald Klein,’ Callson said from behind her.

‘That was his name?’