It was the pilot’s voice that woke him. He roused himself quickly from his deep, dreamless sleep. The Zaleplon had knocked him out, but also ensured that he woke up feeling alert. Outside it was dark and he could feel that the aircraft was beginning to lose height. Looking around, he saw that the rest of the guys were getting ready for landing, removing their hammocks and settling down in their seats. There was quiet in the cabin – the quiet of anticipation, broken only by the noise of the engines and now by the pilot’s announcement.

‘Gentlemen, we’ll soon be landing at Bagram. To conform with the current night-landing regulations in this operational theatre, we’ll be turning off all lights both inside and outside the aircraft. Please ensure your seatbelts are fastened and your luggage is safely stowed.’

As it always did, it struck Sam as faintly ridiculous that this instruction should be given to a bunch of guys who, only a few hours from now, would be hurling themselves from the back of a plane. But he checked his belt nevertheless.

The lights were switched off soon after that, plunging the cabin into pitch darkness. Looking out the window Sam saw that even the small wing lights were no longer flashing. Down below he could make out an occasional fire, evidence of a settlement in the arid expanse of northern Afghanistan. How many Taliban were out there, he wondered idly, mortars at the ready in the hope that they might see an ISAF forces aircraft in the sky and get lucky with a potshot? If that happened, they’d get to fall from a plane a bit earlier than they expected, so Sam was more than happy to go through the procedure of a blind landing.

Cloaked in that precarious blackness, with only the whining sound of the jet engines for company, Sam felt at once vulnerable and strangely comforted. Darkness suited him. Hid him. As a Blade he’d been taught to live and hide in the shadows, out on patrols, making himself unseen, always being the grey man. That was the drill – disguise yourself whenever possible, then close in on your target and neutralise it. That was really all he knew.

He heard the pilot’s voice, as calm and reassuring as if he had just delivered a planeload of holiday makers to the Costa del Sol.

‘Welcome to Afghanistan,’ he announced, as the plane turned from the runway and trundled towards the main terminal building of Bagram Airbase.

It was only Sam’s second visit to Bagram. Most of his previous ops in Afghanistan had been in Helmand Province, which meant a flight to Kandahar in the south before connecting to Camp Bastion a bit further west. But in the summer of 2006 he and three others had been assigned to a job guarding an Afghan politician with an unpronounceable name who, on the instruction of President Hamid Karzai, was making an under-the-radar deputation to a warlord in Parvan Province. He was an unlikeable man who treated the Regiment unit like his own personal servants. At least, he had on the way there. They had left Kabul in an armoured vehicle and as they approached the warlord’s village they had driven straight into an ambush. The unit had fought their way out of it and hotfooted back to Kabul, noses bloodied but no lives lost. The politician had wet himself in the middle of the firefight, though. He was a lot less bolshie on the return journey. The secret talks, of course, were never held.

Having been here once before, then, Sam knew what to expect. The large runway was surrounded by three big aircraft hangars. Various other support buildings – originally built by the Soviets during their occupation – provided a pretty basic level of facilities to the troops at the base, though lots of them were little more than empty shells, having been destroyed by warring Afghan factions over the years. The airfield itself was surrounded by the enormous, craggy, snow-topped mountains that characterised this part of the world, but these were obscured by the darkness as Sam and the rest of the squadron disembarked into the warm, dry air. Instead, all they could see were the bright lights and bustle of the airfield at work. The loadies had already started to unload their pallets of equipment and forklift them on to a truck, while the guys themselves were directed towards one of the hangars, outside which an American A-10 Thunderbolt was parked. The aircraft had a mouthful of shark-like teeth painted on its nose, from which protruded a 30 mm gun. Even though it was 11 p.m. and still swelteringly hot, a technician was hard at work on the undercarriage – he barely glanced at the men who, almost deafened by the roar of their own aircraft’s engines, walked past him and into the hangar.

It was a huge, cavernous space the size of a couple of football pitches. There were three aircraft housed in there, but hardly any people: just a British Army representative who ushered them in towards the right where an area had been walled off with some temporary partitions. Waiting for them was a man in regular civvies. He wore square glasses with titanium rims and had a tanned face that was beginning to show signs of age. His hair was black, though, with no sign of grey: it was impossible to tell how old this man was and his expression was similarly inscrutable. Sam remembered Whitely saying that a representative from the Security Service would be waiting for them. The moment he saw him, one word went though Sam’s head: ‘wanker’. The very sight of him filled Sam with a sudden, burning anger.

Once the squadron was assembled, the man spoke – the clear, confident voice of someone used to talking in public. ‘Don’t get too comfortable, gentlemen,’ he announced. ‘You’ll be going in tonight.’ He looked around. ‘Air troop sergeant?’

Mac stepped forward.

The spook nodded. ‘Get your lads together. The rest of you, remain on standby.’

The British Army representative spoke up. ‘You can get food at the PX,’ he announced. ‘And I’ll show you where you can bunk down.’ He walked back towards the entrance of the hangar. There was a brief moment of camaraderie among the men – those who were remaining on standby briefly shaking hands with those going on the op. Nothing over the top. Nothing showy. Nobody said ‘good luck’; nobody said anything at all, really.

The others quickly melted away, leaving the eight members of air troop alone with the spook. There was Sam and Mac, Craven, Tyler and Cullen; and three others. Matt Andrews was the troop medic. He was black-skinned with short, cropped hair and a quiet, serious manner. Steve Davenport was one of the regiment’s parachute instructors. He’d done more HALOs than most of the guys had had hot dinners; he’d taught half of them everything they knew and it was always good to have him along during an airborne insertion. And finally there was Hill Webb. Real name Hillary, but call him that and you’d be given a pretty swift demonstration of the Regiment’s more advanced fighting skills. Sam had always found him to be a testy little fucker, but sometimes that was exactly what you wanted.

‘You’ve been briefed on the basic nature of the operation?’ the spook asked when they were all alone. It was only half a question, though, and didn’t require an answer. He turned and led them to a corner of the partitioned room where a large whiteboard had been erected. Two maps were pinned to the board, both of them a couple of metres square. One was an aerial view of a piece of land, crystal clear. It looked like it had been photographed from only a hundred metres up, but in fact it was a satellite image. Next to it was a simple map, a line drawing showing the salient areas of the region in more detail.

‘Your objective is here,’ the spook told them, without preamble. He pointed to three long, rectangular-shaped buildings, set at right angles to each other in a horseshoe arrangement with a small, separate building, not much bigger than a shed, at the north-west corner. Arcing round from the south of the training camp to the west was a thin band of forest. Sam glanced at the scale and estimated it to be about two hundred metres deep. North of the camp and the forest, running west to east was a perfectly straight road. Still further east, stretching further than the boundary of the maps, was what looked like agricultural land. The spook pointed at it. ‘Hemp plants,’ he told them shortly. ‘This area is known as the Chu Valley. It ’s a major centre for marijuana production. There are no major settlements close by, but you need to be aware of the possibility of hemp farmers moving their product up and down this road under cover of night.’