A story of Igor Kurchatov - a father of Soviet nuclear weapons.
| Actor | Role |
|---|---|
 Sergei BondarchukIgor Kurchatov | Igor Kurchatov |
 Georgi ZhzhyonovVitaliy Zubavin | Vitaliy Zubavin |
 Nikolai Volkov St.Abram Ioffe | Abram Ioffe |
 Irina SkobtsevaMarina Kurchatova | Marina Kurchatova |
 Nikolay BurlyaevFedya | Fedya |
 Alla PokrovskayaTanya | Tanya |
 Yakov TripolskyStalin | Stalin |
 Mikhail UlyanovZhukov | Zhukov |
 Sergei YurskyRobert Oppenheimer | Robert Oppenheimer |
 Oleg BasilashviliBoris Pash | Boris Pash |
 Alla DemidovaJane | Jane |
 Innokentiy SmoktunovskiyRoosevelt | Roosevelt |
 Fritz DiezHitler | Hitler |
 Aleksandr IvanovNot listed | Not listed |