In this episode we discuss the "Dyatlov Pass incident". It was an event in which nine Russian hikers died in the northern Ural Mountains between 1 and 2 of February 1959, in uncertain circumstances. The experienced trekking group from the Ural Polytechnical Institute, led by Igor Dyatlov, had established a camp on the eastern slopes of Kholat Syakhl.

The students’ trip was supposed to take three weeks. Igor - who was leading the trip - had promised to send a message to the sports club in Sverdlovsk as soon as his group was safely back at their base around 12 February. At first nobody was surprised they didn’t return on time. They had been delayed before because of bad weather.

But by 20 February, their families became worried and raised the alarm. The university sent out a search party of student volunteers. Now in his 80s, Mikhail Sharavin, was one of them.

He was flown to the region by helicopter along with the other volunteers. They split into smaller groups and followed some ski tracks which came to an end at the edge of the forest before climbing up the pass.

“We had gone about 500 metres when on the left I saw the tent,” says Sharavin. “Part of the canvas was poking out but the rest was covered in snow. I used an ice pick lying nearby to uncover the entrance.”

Inside, he and another rescuer found a blanket and some rucksacks lined up neatly and a pile of boots in one corner. There was also the route map, official papers, money, and a flask of alcohol.

Next to that, he spotted a plateful of salo - white pork fat - a Slavic delicacy and the sort of high-calorie food that hikers take with them into the mountains. “It was sliced up as if they were getting ready to have supper or something and didn’t have time,” says Sharavin.

It was then that he noticed the tent had been slashed open from the inside with a knife. Maybe they were in a desperate hurry to get out, he thought, but why? Then he came across something even stranger.

Just outside the tent, he saw frozen footprints made by eight or nine people who were wearing socks, a single boot or were barefoot. The tracks continued for five to 10 metres and then they disappeared.

Sharavin and his friend were dumbfounded. They wondered what on earth could have made the students leave their shelter semi-clad when it was at least -20C outside.

They immediately skied downhill to tell the others in the search party what they had found. Later, when they sat around the campfire for their evening meal, Sharavin produced the flask of vodka that he’d found in the tent and proposed a toast to the health of the Dyatlov group.

“We shared it out between us – there were 11 of us, including the guides,” he recalls. “We were about to drink it when one guy turned to me and said, ‘Best not drink to their health, but to their eternal peace.’”