The five-part drama follows the 1986 nuclear disaster that sent the USSR into an environmental tailspin.

Jared Harris, Stellan Skarsgård and Emily Watson have all joined the cast of the five-part miniseries, Chernobyl. The period drama will follow the 1986 nuclear disaster that triggered the evacuation of a Ukranian city. The production comes from HBO and Sky, the same partnership that brought The Young Pope to the U.S.

Harris (Mad Men, The Crown) will star as Valery Legasov, the Soviet scientist chosen by the Kremlin to investigate the accident, while Skarsgård (Melancholia, Good Will Hunting) will play Boris Shcherbina, the man responsible for leading the USSR government commission in the wake of the disaster. Watson (Genius, The Theory of Everything) will portray scientist Ulana Khomyuk, who was tasked with getting to the bottom of the deadly accident.

The series is slated to start filming this spring. Check back for more casting updates.