‘I wasn’t trying to draw a parallel, merely illustrating that shit happens. It happens to people it shouldn’t happen to, people who’ve done nothing to deserve it. It even happens to pet rabbits. There’s not much we can do but face up to reality.’

‘It didn’t just happen though, I pulled the trigger.’

‘You pulled the trigger, but if al-Qaeda hadn’t carried out the 9/11 attacks you wouldn’t have been there in the first place. If the CIA hadn’t funded the Mujahideen in their fight against the Soviet Union in the eighties then perhaps Bin Laden wouldn’t have risen to prominence. And so on. How far back do you want to go?’

‘I pulled the trigger.’ Silva repeated the bare facts she’d mulled over so many times. Felt the tears coming yet again. ‘In the end it was down to me.’

‘Sweetheart.’ Her mother raised a hand and stroked Silva’s hair. It was as if Silva was a child once more. ‘It hurts me to see you like this. At some point you have to move on.’

‘I know.’ Silva had told herself as much dozens of times, but the words refused to alter the reality of the situation. Still, her mother was correct, and invariably the advice she gave was the right course of action. ‘I’ll try to put it aside while I’m here.’

‘There’s no need to do that, we’ll give it a good talking over, right?’ Francisca smiled. ‘But perhaps leave it at the airport with the unclaimed baggage when you return to the UK, yes?’

Silva nodded and changed the subject. ‘What will we do?’

‘See the museum, go to the beach, visit the souks, eat, drink, and – this most important of all – laugh!’

They’d done all of that and, for the week she’d been there, Silva had almost forgotten about Afghanistan. When they parted in the departure hall at the airport, she’d kissed her mother and waved as she passed through to airside. She’d turned back to see her mother fumbling with a piece of paper, unfolding it, and waving it above her head. It was the sign she’d held up when Silva had arrived: BecBec.

‘Au revoir, BecBec,’ her mother shouted. And then, in Portuguese, ‘Até breve.’

See you soon…

The document Holm had cobbled together on the day of the attack hadn’t been received well, and Huxtable gave him two weeks to write a full report.

‘Something I can show to Thomas Gillan,’ she said. ‘Something he can show to the prime minister. Pretty pictures and pie graphs. Lots of confusing figures. Plenty of footnotes and appendices. You know the kind of thing.’

When he strolled across Vauxhall Bridge and met Palmer for lunch in a pub round the corner from the SIS building, Palmer reached out a hand and patted Holm on the shoulder.