Medev followed them into the forest, lifting his feet up to his knees with every step he took through the deep snow. The weak light of the day was almost completely gone, but after ten minutes of following the path Medev saw two hunched-over figures a hundred metres ahead of him. They turned, saw him, and began to desperately scramble away. Medev called out to the men to stop, but they wouldn’t. He was forced to chase them. By now the snow was up to his thighs and pushing through it was exhausting. He had no idea how the prisoners were managing it, or how long it had taken them to get this far.

‘Stop!’ he shouted again.

But they kept struggling through the snow, grabbing onto each other and the bare trunks of trees to push themselves on until they finally tripped over something hidden in the snow and crashed into a drift.

It took a full minute for Medev to reach them. When he did, he saw that one had a makeshift splint on his right leg, and they were both so gaunt and grey he could barely believe they were still alive at all. He knew there was no way they could survive the journey back to Solovki, or whatever punishment the other guards might inflict on them for their attempted escape: He also knew they’d never survive a night in the snow without shelter. From the looks in both men’s eyes, they knew all this too.

They gave up trying to struggle to their feet and just half kneeled, half slumped in the snow.

‘Please,’ one of them whispered.

It was so dark by then that Medev couldn’t tell which one of them had said it, but he understood what they both wanted. He pulled his pistol from the leather holster on his hip and shot them each in the head. The deep scarlet blood was slow to seep out of their frail, withered bodies. Ten minutes later two more guards arrived, alerted by the sound of gunfire. The next day Medev was promoted.

He was brought out of his memory as the Tu-104 touched the runway at Petrozavodsk airport. The plane taxied to a halt next to a large, black GAZ M21, freshly polished by the local KGB office in preparation for his arrival.

As he sat in the back seat he was handed a slim manila folder—the latest casualty and assessment report from Povenets B. It was considerably more detailed than the one that had been dispatched to Moscow. It also showed just how much that report had played down the scale of the disaster.