On June 16, 1984, strange lights were seen over the distant and isolated farming settlement of Saraa in the Mongolian People’s Republic, as reported by a group of Soviet troops on exercises in the nearby mountains. The central government in Ulaan Bataar reported that their sole link with the isolated community, a telex line, had been cut off.

Concerned–the hills had been a refuge for pro-Buddhist rebels during the collectivization of the country in the 1930s–the governor of Ömnögovi Province asked the Soviets to investigate and to garrison Saraa temporarily. The troops found nothing amiss, and settled down for what they thought would be a leisurely occupation–a furlough from their intense training and expected combat deployment to Afghanistan.

Within a month, nearly all of the 250 men who had been stationed there were dead.

The first deaths occurred when army rations ran out and the Soviets began eating local foods. Dozens died instantly or in the following hours due to what the regimental medic described as an “intense allergic reaction.” Puzzled, the Soviet commander rounded up locals on suspicion of poisoning his men, but no evidence could be found.

Eventually, despite generous gifts of food from the locals, the other Soviets began exhibiting signs of acute malnutrition and starvation. For some reason, only their army rations seemed to have any nutritive effect at all; Merchants from relatively nearby communities and Saraa citizens returning from trips suffered the same fate. The locals and the provincial government in Dalanzadgad could not explain why.

Eventually, the Soviet commander pulled his troops out and recommended a full quarantine to deal with a suspected bioagent. Scientists from the Vozrozhdeniya Island biological weapons unit, in full NBC containment gear, found nothing. The only effects they noted were a number of odd quirks: nearly all the residents had become left-handed, for instance.

Eventually, the quarantine was made permanent, and it survived democratization. Until a group of missionaries arrived in Saraa nearly 25 years later, no Mongolian or foreigner entered or left the village.