A moment later, Carr’s mobile rang.

‘Yes?’ he said. ‘I’m busy.’

‘Sorry to bother you, John,’ said Justin Nicholls. ‘I wondered if you could spare me half an hour?’

‘What for?’

‘I’d rather talk in person.’

Carr sighed.

‘When?’ he said. ‘Where?’

‘Two minutes,’ said Nicholls. ‘That’s me ringing your buzzer now.’

Carr pulled his training bottoms and top back on and opened the front door to his flat, looking down at the faint mark on the wooden floor where the IRA assassin Dessie Callaghan’s lifeblood had pissed through his carpet a few months earlier.

He had planned to replace the ruined carpet, but in the end he’d decided to stick with the wooden floorboards underneath. He’d had the blood cleaned away, but rather than sanding the last vestiges of the stain out of the boards he’d had it varnished over: seeing it sharpened his wits, and was a nice reminder to take nothing for granted.

‘Ten minutes,’ he said, when Nicholls poked his head inside. ‘I need a shower, and then I’m going out.’

Nicholls followed him through to the living room, and sat on the sofa Carr indicated.

‘Thanks, John,’ Nicholls began. ‘I must say, it’s…’

‘What do you want, Justin?’ said Carr.

The MI6 man hesitated.

‘John,’ he said. ‘You’re no longer serving, so… I need to be careful, here.’

‘I understand,’ said Carr. ‘You know where the door is.’

Nicholls hesitated again.

Then he said, ‘Fair enough. The Prime Minister’s daughter and her friend are being taken to Sirte, in Libya. A very dangerous place, as you know.’

Carr nodded.

He knew that stretch of north Libya well.

His mind’s eye was showing him pictures of the main Tripoli-to-Tobruk highway on the outskirts of the city.

To the north, the Mediterranean Sea – that barrier between the familiar comforts of Europe and the savage, untamed wildness of North Africa.

To the south, stony desert, irrigated farmland.

Kids playing football. Women in burqas. Men with suspicious eyes.

The usual donkey-carts pulling water bowsers, or laden with date fronds.

That sulphurous, background stench from the stagnant saltwater lagoons in the marshland to the north, blending with thin, acrid smoke from oil-barrel rubbish fires outside every other home.

Gaddafi had gone to school in Sirte, and had long dreamed of turning it into the capital of a future United States of Africa, with landscaped gardens, wide boulevards and impressive buildings. Those grandiose dreams had died with him, when rebels had caught him hiding in a sewage pipe during the civil war of 2011. By then, the place had been bombed to fuck and it was still in the slow process of rebuilding.

‘Who’s in charge?’ said Carr.

‘Nominally, the North Libyan Transitional Authority,’ said Nicholls. ‘In reality, it’s in possession of a loose collection of local tribal groupings, and militias. Precisely who the boss is, if there even is one, we don’t know.’