April 26, 1986, Ukrainian SSR. Plant workers and firefighters put their lives on the line to control a catastrophic 1986 explosion at a Soviet nuclear power plant.

Lyudmilla Ignatenko, a Pripyat resident, ignores warning about her firefighter husband's contamination. Valery Legasov lays out a decontamination plan, complete with human risks.

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