August 1953. The young Muscovite, Maxim Smirnov, assistant to the chief operator, arrives in Semipalatinsk with a film crew. The purpose of their mission is kept in the greatest secret. It is there, in the steppes of Kazakhstan that he meets his first love, the young Dinara. The young people do not know that they are at the epicenter of an event that will change their lives forever and also the life of all humanity. It is indeed there, in Semipalatinsk, during this very hot summer that the experimentation of the first hydrogen bomb will take place.