“Plastique,” Chavasse said.

“Totally harmless until used in conjunction with one of these timer pencils.” Ram Singh held a few up. “Five-minute fuses, but the two with yellow ends are two minutes.”

The haversack was put on Chavasse’s back, then he pushed his arms through the straps. One of the officers helped him into a parachute, another gave him a Sten gun with two magazines taped together, which he draped across his chest.

Ram Singh picked up a weighted signal can with a great scarlet streamer attached to it. “The message for Major Hamid. It tells him exactly what you intend.” Ram Singh put a hand on Chavasse’s shoulder. “I hope he finds it possible to… how shall I put it… to retrieve you, my friend.”

“He’s a Pathan,” Chavasse said simply. “You know what they’re like. He’d walk into the jaws of hell just to have a look.” He smiled. “I’d better get moving.”

Ram Singh pulled on a parka and led the way out. It was snowing a little, loose flakes on the wind and very cold. They crossed to the Navajo, where Piroo already had the engines warming up. Chavasse paused at the bottom of the Airstair door and Ram Singh shook hands and saluted.

“As God wills, my friend.”

Chavasse smiled, went up the steps and pushed the door shut. Piroo glanced over his shoulder and boosted power, then they roared along the airstrip and lifted off.

In spite of the layers of clothing he wore, Chavasse was cold – very cold – and he found breathing difficult. He looked out of the window to a landscape as barren as the moon, snow-covered peaks on either side. Now and then they dropped sickeningly in an air pocket, and they were constantly buffeted by strong winds.

Piroo glanced over his shoulder and shouted above the roar of the engines.

“I’ll curve round to the gorge first. Let’s make sure the Chinese are still on the other side before we communicate with Hamid.”