Jonah dropped Lightman back at the station and picked up O’Malley, who had printed out photos of the victim. His Irish sergeant was generally the preferred choice for casual meetings with witnesses, assuming he was actually somewhere to be found and not off pursuing his own leads. There was a warm humour to him that both disarmed the more obstructive folk and encouraged the more helpful ones to bend over backwards.

‘Are we headed to Blue Underground for some moody daytime drinking?’ O’Malley asked, once he’d levered himself into the car.

‘You know it?’ Jonah asked, with interest.

‘I met a witness there once.’ O’Malley shrugged. ‘It’s OK. Cocktails and a pretentious DJ one floor down, and an eighties disco cheese-fest the floor below. But it’s not drugged up, and there’s not a lot of brawling, either.’

Jonah nodded, remembering that it was the expensive, exclusive Midnight Bar that had been closed down a few years ago after a drugs bust. The most likely clientele for party drugs were, it turned out, wealthy men and women in their forties.

Twenty minutes later, Jonah pulled into a pay and display space a few yards down from the club. The doorway to Blue Underground lay between an estate agent’s on one side and an oriental food shop on the other. The sign above it spelled out the name in cursive lettering on a midnight-blue background, and almost managed to look classy.

They made their way down the stairs and turned the corner to find the entrance barred by a security door. The sound of a vacuum cleaner came from just beyond it, and Jonah rapped sharply.

The vacuum cleaner grew louder and then ceased, and a middle-aged Latino man wearing a black polo shirt and matching trousers opened the door.

‘DCI Sheens,’ Jonah told him. ‘I spoke to Charlie earlier.’

He let them into a slightly featureless corridor and pointed them down to a bar at the far end. Bright overhead lights had turned what was presumably a dimly atmospheric night-time grotto into a slightly tatty-looking cellar. The chairs were all up on the tabletops, and there were boxes of beer standing on the bar, where a tall thirty-something man with a Mediterranean look was discussing stock with a diminutive girl in another black polo shirt.

‘Would you be Charlie?’ Jonah asked him.

The man turned, revealing a cheerful, tanned face marred by a bruise on his cheekbone.

‘Yes. You’re the police?’ He moved to the end of the bar and walked round it. ‘Come and have a seat. We’ve got coffee if you want it?’

His accent was pure Sheffield, and the chirrupy manner was encouraging. He liked their chances of getting as much help as they needed out of Charlie.

‘No coffee, thanks,’ Jonah said.

‘Joanne, could you make me a cappuccino?’