Plant workers and firefighters put their lives at risk in order to control an explosion at the Chernobyl Nuclear Power Plant.

Nuclear physicist Ulana Khomyuk tries to warn her colleague of a second explosion that could devastate the entire continent.

Valery Legasov lays out a detailed decontamination plan that risks many human lives; Lyudmilla Ignatenko ignores deadly and dangerous warnings about her firefighter husband's contamination, which puts her in the firing line.

Valery Legasov and Boris Shcherbina contemplate whether to try and detect radioactive debris with lunar rovers; Ulana Khomyuk experiences push back from the government, while trying to discover the source of the explosion.

Valery, Boris, and Ulana risk both their reputations and their lives in order to share the truth about Chernobyl.