They hurried out of the city, skirting Zubayr and finding a quiet spot on the road to the north of the Al Mufrash airstrip. The road here followed the route of a dried-out wadi, dipping down into a depression so that the sides rose up four or five feet. It was a natural choke point that would be impossible to evade without backing up.

Faulkner drove on for thirty seconds before running off-road and parked the Freelander behind a grove of palm trees that would hide it from traffic approaching from the southwest.

Beatrix drove around a curve that would hide the Audi until the last possible minute.

They waited. The sky was dark, the stars scattered like diamonds across velvet. The horizon was lightened by the flames from the oilfields, and the sound of machinery was audible from miles away.

She saw a pair of headlights in the distance, heading right at them. She took out her phone and texted the tracker.

It pinged back its response.

A blue dot closing in on her red dot.

Duffy.

She drove the Audi into the middle of the road, leaving it with no room to pass on either side.

She went to the back of the SUV, opened it, hauled Sascha Duffy out and took her around to the side of the car that would face approaching traffic.

“Wait here,” she said. “It’s nearly over now.”

“What are you doing?”

“Wait.”

She went back to the car and took out the FN F2000 assault rifle.

Duffy’s Jeep Grand Cherokee bounced down into the dip, the headlights illuminating the walls of the wadi as it proceeded around the gentle curve.

Faulkner gunned the Freelander’s engine and the SUV shot forward, blocking the way back and sealing Duffy inside.

Duffy exited the corner. The headlights shone over them: Beatrix, with the assault rifle cradled in her arms; his wife, averting her eyes from the glare of the lamps. Duffy hit the brakes and skidded to a stop. He reversed, the tyres chewing gravel as he tried to back away at speed.

The rifle was a bulky bullpup, chambered in 5.56 NATO. She nestled the stock into her shoulder and aimed, squeezing the trigger and sending a volley of bullets into the Grand Cherokee. The headlights shattered, the hood was torn up and both front tyres were shredded. The wheels sank down to the rims and carved tracks through the sand as the rear wheels dragged the disabled Jeep backwards. Beatrix aimed again and sent a volley through the windscreen. The glass crashed out of the frame, and rounds punched up and out of the roof.

Faulkner was out of the Freelander and approached the beached Jeep with his pistol raised. He fired, taking out the rear tyres and then the rear windscreen.

They both stopped firing.

Beatrix walked to the Jeep, the FN F2000 aimed straight at Duffy and her finger on the trigger.

“Get out!” Beatrix yelled over the sound of the still-straining engine.