‘The ceremony is everything,’ Joe said. ‘The ritual seems to be at least as important as the punishment. Both of these killings have been as choreographed as anything you would see at the Old Bailey. But instead of wigs they wear black masks. Instead of a judge and jury it’s the unsubs. And in the dock, you have the accused.’

‘With no chance of getting a suspended sentence,’ Whitestone said.

‘But the ritual – the ceremony – whatever you want to call it – is a statement and a warning. And, above all, it’s an expression of power,’ Dr Joe said. ‘That’s the crucial thing. It’s an expression – and a reaffirmation – of power. In a normal court of law it is a reaffirmation of the power of the state. The unsubs no doubt see what they’re doing as a reaffirmation of – I’m guessing here – some higher form of justice, some higher and more noble and less fallible law. A reaffirmation of the power of the people.’

‘Got it!’ Wren shouted. ‘The name of the victim!’ She listened to her phone and I saw her face register something that I could not read. ‘And the name of the kid on the wall,’ she said, all the euphoria suddenly leaving her. She ran her hands through her red hair and slowly hung up the phone.

‘OK,’ she said. ‘The victim of the hanging is – was – Hector Welles. Thirty-five years old. Single. A trust fund manager in the City. Sent down for causing an accidental death while driving.’

‘The boy on the wall,’ I said.

Edie nodded. ‘Welles was driving his Porsche 911 when the kid rode his bike into the street.’ She hit her keyboard and the same photograph of the smiling boy filled the giant TV screen.

‘The child was killed outright?’ Whitestone said.

‘He was in a coma for six months. In the end the parents switched off the life-support machine. The boy’s name was . . .’ She glanced down at her notes. ‘Daniel Warboys,’ she said.

I took a breath.

‘Daniel Warboys? What part of the world was he from?’

‘West London. Hammersmith.’

‘Do you know this child, Max?’ Whitestone said.

‘I think I’ve met his grandfather,’ I said. ‘Paul Warboys.’

There was silence in MIR-1.

‘The Paul Warboys?’ the Chief Super said.

I nodded.

Paul and Danny Warboys ran West London back in the day when Reggie and Ronnie Kray were running the East End while Charlie and Eddie Richardson ruled the roost in South London.

I could easily believe that Paul Warboys had a grandson named after his beloved brother Danny.

‘How long did Hector Welles go down for?’ Whitestone asked.