Both were then taken back aboard the helicopter by the two youngest SBS men, who would ride shotgun with the body of Emily Souster as it was flown to Spain.

As an avgas refuelling hose was attached to the Wildcat, SSgt Dave Cummins went with the first lieutenant to the bridge, where the Westminster’s skipper was waiting to take possession of the digital camera, so that the photographs taken by Trigger Stevens could be sent to London via the secure sat-link, as per his orders.

Back outside, the pilots did a quick torchlight walk-around of their refuelled aircraft in the humid night air. Satisfied, they took off again at a little after midnight, and made straight for Morón Air Base, some 300km north and a little over an hour’s flying time away.

There a giant USAF Boeing C-17 Globemaster would take over, transporting Emily Souster’s remains and the forensic evidence the 1,650km to RAF Brize Norton in Oxfordshire.

In London, the Metropolitan Police’s Evidence Recovery Unit – among the world’s foremost experts in DNA recovery, and sundry other tricks of their trade – were already standing by to begin work.

Their first task would be to match Emily Souster’s DNA with that of her heartbroken father to confirm what they already knew.

Chapter 50.

50.

NOT LONG AFTER the helicopter lifted off, a liaison officer at Navy Command HQ on Whale Island telephoned Justin Nicholls at MI6 to confirm the success of the mission, and to say that a full file would be sent across shortly.

As he replaced the receiver, Nicholls allowed himself a fleeting smile. The knowledge that he’d been able to have some small practical input into an investigation which now involved hundreds of police officers, spooks and military personnel in a dozen countries was satisfying.

The smile vanished a moment later, when his secure line buzzed for the hundredth time that day.

It was a senior officer called Kate Carver.

‘We have something for you, Justin,’ she said.

‘Fire away,’ said Nicholls, suppressing a yawn, and looking at his watch. It was well past midnight, UK time, and he’d been in the office since 6 a.m.

‘A video was released on various online platforms fifteen minutes or so ago. Originated in the Ivory Coast, and now being shared across multiple accounts. It shows the three women kneeling at gunpoint, and then the murder of one of them.’

The hair on the back of Nicholls’ neck stood up, and his body buzzed.

‘Emily Souster?’ he said.

‘Yes,’ said Kate Carver. ‘She gets shot in the back of the neck by a man wearing a balaclava. He waits a few seconds, then he shoots her again to finish her off.’

‘Any statement?’

‘The usual theatrical nonsense,’ said Carver. ‘A warning to Britain. They call themselves Warriors of Jihad.’

‘How original.’

‘Quite.’

‘Is it on the TV news yet?’ said Nicholls. ‘I’ll need to tell the PM.’