Plant workers and firefighters put their lives on the line to control a catastrophic 1986 explosion at a Soviet nuclear power plant.

With millions of lives already at risk, Ulana races to warn fellow Soviet nuclear physicist Valery Legasov about the threat of second, devastating explosion.

Valery Legasov draws up a plan, but it comes with great human risks. Lyudmilla ignores warnings about her firefighter husband's contamination.

Legasov and Shcherbina consider using lunar rovers to remove radioactive debris, while Khomyuk faces government hurdles in determining the truth about the cause of the explosion.

Legasov, Shcherbina and Khomyuk risk their lives and reputations to expose the truth about Chernobyl.