Swire cut him off with a short jerk of her head.

‘Let’s skip the tech talk, shall we?’ she said. ‘But tell me this: how likely is it that the average social network psycho would have security architecture that elaborate?’

‘It would be . . . unusual,’ Gane answered.

Swire may not have cocked a disbelieving eyebrow. But that was the impression she gave.

‘Only unusual?’ she said quietly. ‘Really? No more than that?’

‘It would be unprecedented, ma’am.’

Swire nodded, as if we were at last getting somewhere.

‘What’s the latest on prints?’ she said. ‘Are we working the prints?’

Mallory’s fingertips brushed his SIO policy book. He cleared his throat.

‘The situation is unchanged, ma’am. We have no prints at any of the crime scenes.’

Swire stared hard at him.

‘You mean you have smooth glove prints?’

‘No prints, ma’am. No smooth glove prints, no partials – no prints at all. The absence of prints remains . . . unexplained.’

Swire let this sink in.

‘So he’s a ghost?’ she said.

The base of my spine pulsed with pain.

‘He’s no ghost,’ I said. ‘Ma’am.’

She nodded, as if she had only just decided something.

‘We’re rebooting Operation Fat Boy,’ she said. ‘I’m bringing in three new bodies.’

Swire was flanked by two men who had remained silent throughout the meeting, avoiding eye contact with the incompetent Murder Investigation Team from West End Central: a young East Asian in glasses with digital geek written all over him, and a much older man, about sixty, with soft white hair who couldn’t possibly have been a part of the Met because he was wearing a suit but no tie.

Now they stirred.

Swire nodded curtly at Mallory and told him, ‘You will remain as SIO for the time being. But I’ll be sitting in at the morning briefings and you will be reporting directly to me.’

Gane and Whitestone exchanged a look. Mallory’s time was passing. He was still senior investigating officer but this no longer felt like his investigation. Operation Fat Boy now felt like it was being run from Broadway, SW1 – New Scotland Yard – not 27 Savile Row.

Mallory was a good man, but the world was beating him down. Suddenly his authority felt like a fragile thing that could be taken away by one gesture from the woman at the top of the conference table. I saw that Gane and Whitestone could not look at him.

Swire gestured to the digital geek on her left. ‘This is Colin Cho of the Police Central e-crime Unit. As you know, the PCeU is jointly funded by the Home Office and the Met to provide a national response to the most serious incidents of cyber-crime. Bob the Butcher comes under their remit.’

‘Hopefully we might be able to show you a few new tricks,’ Cho said to Gane, his accent somewhere between Hong Kong and London.

Gane said nothing.