The brilliant scientist Mikhail Rubin ends up in the camp because of a personal conflict with the People's Commissar Beria. But suddenly Rubin is released: his best friend and colleague Kirill Muromtsev recommended Mikhail to a secret project to create a Soviet atomic bomb, and the physicist's candidacy was approved by academician Kurchatov. Mikhail returns to Moscow and finds out that while he was in the camp, his fiancee Anna Galeeva managed to become Kirill's wife. To fulfill the task of the state, young scientists will have to work together, despite the personal drama.