The islands were not hospitable. Living conditions for the NKVD interrogators, their staff, and the prison guards were harsh. For the prisoners, they were wretched. Many of the academics and intellectuals imprisoned at Solovki lost limbs either to frostbite or to forced labour. Others simply died overnight as temperatures, already below zero during the short days, plunged even further in the long nights.

Medev was a promising, young NKVD lieutenant when he was sent to Solovki. It was a formative experience. For five months, he saw first-hand the casual ruthlessness of absolute power, and learned how much ambition could advance your standing in Stalin’s world, and how much could see you ending up in a mass grave. He also saw that doing what was right and doing what was right in the eyes of the Party were not always the same thing, even if they looked like they were.

The Solovetsky Monastery had originally been taken over to house forced labourers during the construction of the White Sea Canal, which would eventually link the Arctic coast to the Baltic Sea. By 1937 the first section of the canal had been completed and work had moved west.

The White Sea froze over in winter, and the thick ice could damage the entrance of the canal if it was left to build up. So, every day during winter fifty prisoners were taken out across the frozen sea to break the ice at the mouth of the canal. Because of the obvious opportunities for escape, extra men were drafted in for guard duty, often including Medev.

Prisoners, wearing whatever heavy rags they could find, would be marched from the camp before the sun rose, watched over while they worked for six hours without rest or food, and then marched back after the sun had fallen again. Some perished before they even reached the canal, and more as their bodies finally gave up after hours and hours of brutal work. The ones who managed to survive the day tended to make it back to the islands, the prospect of a metre or two of dry floor to rest on suddenly enough to keep them going.

None of the guards paid particularly close attention to how many prisoners died on any day, but one night, as the men were being lined up to head back across the ice, Medev sensed that there weren’t enough of them still standing. He quietly left his position at the back of the loose column and walked towards the forest that ran near the edge of the canal. He immediately saw a messy path cutting through the trees. It looked like two sets of footprints, lopsided as if each was dragging the other.