They drove east and then north, away from the river. Bowman sat in the back, fighting off a wave of exhaustion. Things were moving fast. Faster than he’d expected. Bowman had assumed that the UKNs would ferry him back to his hotel after the meeting with Mallet. He could pop a couple of pills, get his head down and grab a few hours of kip, before getting a full briefing the next morning.

Instead, they were going straight to work.

Push through it. There’ll be plenty of time to rest later.

Buzzcut kept the BMW ticking along as they motored through Aldgate. They passed a chaotic mishmash of ancient churches, newbuild apartment blocks and fried chicken shops. Fragments of the old city poked through the clutter: an old-school boozer named after a long-dead admiral, a greasy spoon, a curry house that looked as if it had been doing business since the Gordon Riots. Buzzcut made several quick turns, and then they rolled down a wide street flanked by steel-and-glass apartment blocks and trendy co-working spaces. At two forty in the morning, the streets were empty. After three hundred metres Mallet motioned for him to pull over.

‘OK,’ Mallet said. ‘This is fine.’

Buzzcut parked the BMW at the side of the road but kept the motor running. Bowman looked enquiringly at Mallet. They had been driving for about six minutes since setting off from the old Royal Mint.

‘The Cell is here?’

‘Get out,’ Mallet said. ‘Follow me.’

They slid out of the back seat, breath misting in the night air. Henderson swerved round to the boot, popped it open and handed the leather holdall to Bowman. He dived back into the front passenger seat, and a few moments later, the BMW sped away.

Bowman followed Mallet as he started across the road, towards a drab grey building sandwiched between a gastropub and an accountancy firm. Blinds covered the windows on every floor of the building. There was a canopied entrance, but no company sign. Nothing to indicate what sort of business went on inside.

‘What is this place?’ asked Bowman.

‘Used to be a police station,’ Mallet said. ‘Back in the seventies. Before your time. It closed down a few decades ago. Been empty ever since. There’s a range in the basement. The lads in SO19 use it for shooting practice, but no other fucker knows about it.’

‘This is where you lot are based?’

‘For now. Some day, it’ll be sold off to a property developer for big bucks,’ he grumbled. ‘But for now, this is our HQ.’

Bowman gazed up at the six-storey building. In his head, he’d imagined the Cell would be based somewhere remote, far from the public eye. A disused industrial estate in Hertfordshire or Essex, maybe. Not a few minutes’ walk from the bustle of the City.

‘Isn’t this a bit conspicuous?’ he asked.