‘Could someone have snuck it out of a base?’ said Bose. ‘It’s possible, but not easy, inspector. But there are other ways to get round the system. Weapons malfunction, for instance. These rifles are pretty reliable, but things always go wrong. So they get returned to the armoury, they get cannibalised, some go missing. Of course, the records are supposed to be tight, but mistakes happen and things get taken. And the army has had considerable inventory issues in the last few years.

‘If this rifle was stolen as a one-off, then there’s little chance I’ll be able to find the source. But if it was part of something bigger, say a systematic theft of weapons, then we may have a chance. Let me look through the system – see if I can spot any irregularities.’

‘How long will that take, sir?’ said Bose.

‘A day maybe, maybe more.’

‘Tell you what, Mr Metcalfe, how about three hours?’

#

King’s Cross, London

Stepping into La Traviata was like stepping back four decades, Gabriel thought as her eyes became accustomed to the gloom. It was like a pastiche of an Italian restaurant, designed by someone who’d watched too many 1970s sitcoms, and was littered with red-checked tablecloths, plastic flowers and heavy maroon wallpaper. The terrifying Neapolitan owner welcomed Gabriel like an old friend and escorted her to the table with more flourishes than were strictly necessary. Gabriel had eaten here four or five times and she no longer bothered giving her order. The owner was convinced Gabriel only wanted spaghetti al pomodoro and refused to be persuaded otherwise.

Gabriel rarely had time for lunches like this, but Rachel Isaacs, with her Mossad connections, was worth pursuing. Isaacs had been surprised to take the call last night, but had agreed to meet today. Gabriel and Isaacs had lived in the same halls of residence in their first year at Nottingham and had met during an uncomfortable 1960s-themed fresher’s disco. They found solace in each other’s awkwardness at the enforced jollity of the event, and the bond formed by social embarrassment turned quickly into friendship. They had stayed in touch after graduating and had met three or four times since Isaacs had returned to the UK a few years earlier, nominally working in the Israel embassy’s cultural department.

She was already waiting at the table and seemed ageless, thought Gabriel, as Isaacs rose to kiss her, the same straight black hair, cut shoulder-length, the same clear and clever brown eyes and quizzical half-smile. They chatted, passing on office gossip and discussing politics until the food arrived.

‘I had a look this morning and we’ve got nothing on your old pal Abu Mujahid, sadly,’ said Isaacs. ‘He was last seen in Syria six months ago and has gone off the radar.’

‘That’s what I keep being told,’ said Gabriel.

‘But we’ve got something on an associate of his. Have you come across the Global Islamic Defence? They’re fairly new players.’

‘I’ve heard of them,’ said Gabriel. Jihadist splinter groups were emerging from the ruins of the so-called Caliphate all the time, all with new names – even when the faces, slogans and goals usually remained the same. Some went by half a dozen different names, which made tracking them hellish.