**_What happened to nine Russian hikers on Dyatlov Pass in early February, 1959?_** British-American documentarian Liam Le Guillou travels to the area in question in the northeast Ural Mountains to talk to the locals and examine the best theories as to why the nine athletic Russians (seven men and two women) left their tents in the freezing cold of the night without adequate attire, with most perishing of hypothermia far away and a few others revealing signs of blunt force trauma. “An Unknown Compelling Force” (2021) is worthwhile for learning about the nine victims, as well as the inaccessible region in general. Yekaterinburg is the closest city, which is 340 miles to the south; and the closest town like 60 miles away. Seven of the nine hikers were college students with the other man a healthy veteran of WW2, fifteen years their senior. They left behind undeveloped film and diaries up until the day of their deaths for evidence of what went down, not to mention their grisly remains and the autopsies thereof. While Le Guillou wisely leaves the mystery open at the end, he also doesn’t fail to point out what he thinks likely went down with the help of various experts and investigators, Russian and American. Certain popular theories, including the outlandish ones, are ruled out for one good reason or another, which leaves the most obvious scenario, according to Liam and his experts. Simply put, they believe the hikers were murdered, possibly by a savage band of Khanty living in the area, who wouldn't take kindly to Soviet invaders, especially if they inadvertently marred one of their shrines. While this theory is interesting, there wasn't any evidence at the scene of these supposed assailants, like footprints. The better theory is that 3 feet of shifting snow during the snowstorm suddenly fell on the tent at night, which panicked the nine inhabitants. Fearful of an actual avalanche, they cut themselves out of the tent and fled without proper attire. When they realized an avalanche_ wasn't_ going to happen, some tried to make it back to the tent but died of hypothermia in the -13 degrees Fahrenheit weather (it was no doubt difficult to find the camp in those conditions). What happened to the others is well explained in an 11-minute documentary called "Is Dyatlov Pass Mystery Finally Solved," available for free on Youtube. This film runs 1 hour, 46 minutes. GRADE: B-