In Episode 3, Libby covers the tragic and mysterious incident of the Dyatlov Pass where 9 Russian hikers died under suspicious circumstances.

Sources:

https://en.wikipedia.org/wiki/Dyatlov_Pass_incident

https://www.theatlantic.com/international/archive/2020/02/russia-dyatlov-pass-conspiracy-theory/605863/

https://www.bbc.co.uk/news/extra/SoLiOdJyCK/mystery_of_dyatlov_pass

https://www.rbth.com/history/331729-dyatlov-pass-incident-theories

https://www.google.com/amp/s/arstechnica.com/science/2022/03/confirmed-avalanche-is-likeliest-explanation-for-tragic-dyatlov-pass-incident/amp/

https://www.google.com/amp/s/variety.com/2021/film/news/dyatlov-pass-incident-unknown-compelling-force-documentary-1234974868/amp/