Nine experienced hikers. Tent cut open from the inside. Found scattered across the slope in various states. One was missing her tongue. Two had skull fractures consistent with a force no human could produce. Radiation was detected on three sets of clothing — the source was never identified.

Soviet investigators wrote in their final report: the cause of death was అజ్ఞాత బలవంతపు శక్తి. The file was sealed for 30 years.

When it was reopened, three pages were missing. The pages that remained contained one recurring margin notation: 7.83. Nobody has explained what it refers to.