Moonlight caught the Kabul River as it broke over rocks. The enemy had taken many precautions against a possible attack only to ignore the river itself. Their thinking was conventional: their orthodoxy would be their undoing. Fahad stepped into the river, stifling a desire to exclaim out loud at the cold. He could hear the sharp intake of breath as his men entered the water behind him. They had no specialist clothing. They’d abandoned the customary loose-fitting shirts, instead wearing American-style T-shirts that didn’t drag in the fast-flowing water. They wouldn’t survive long in these temperatures if their heads or necks became wet. They needed to keep their upper torso dry by navigating through the shallows. Stealth was their only chance of survival, rigging the explosives to detonate and then retreating.

The aim of the operation wasn’t to bring the dam crashing down. Though it would be a glorious sight, it would be an impossible task, even with Samir’s expertise. They were attempting to damage the tunnels underneath it, to cause enough structural instability to shut the facility for repairs. It would cripple operations in Kabul. The Soviet regime would have to concentrate its efforts on energy security, keeping its resources close to the capital, while the resistance could gather strength. It would be a great psychological victory: striking at the heart of the occupation’s source of power the same day as Fahad’s older brother, Dost Mohammad, murdered an entire class of trainee secret-police officers.

As they navigated the final twist of the river, the dam was directly up ahead. The control room could be seen clearly, the men in charge standing at the windows. The river was at its most powerful here, contained within the narrowest area, the speed of flow controlled by the level of discharge from the dam. At the flick of a button the control room could dump water, enough to flood the riverbed, sweeping the team downstream. Several spotlights zigzagged across the valley and across the river, passing directly in front of Fahad. He sank down, his head just above the water. The spotlight moved on.

Within touching distance of the steep concrete face, Samir began his work. The rest of the team took up positions around him. No longer moving, Fahad shivered. He was unable to stop, his hands shaking. Concerned about his brother’s coordination, he moved to help him only to find he wasn’t readying the explosives: instead, he was chipping at the concrete.

—What are you doing?

The crash of the water released from the dam concealed their conversation. Samir said:

—If the explosives are planted just a short depth inside the concrete the force of the explosion will travel inwards, through the structure. It might even bring the whole thing down!

Fahad was furious.

—This wasn’t the plan. We have to damage it, that’s all. A hole is too risky. They’ll hear us! We don’t have time!