A documentary film about the construction of the first atomic power station in Soviet Ukraine in Chornobyl. In the film, schoolchildren, public servants and inhabitants of villages of the Chornobyl region try to answer the question "What is the atom?" Their naive and unsure answers illustrate the vague but decidedly trusting perception of the atomic phenomena. In Soviet cinema of the 1970s, the "production of drama" is popular, a genre in which factory or office routines are presented in a romantic light. The film uses all of these new aesthetic trends in a documentary approach. The ambitious construction plans of the power station are shown through a number of personal stories, one of them is about an engineer's dream of a river port in the "atomohrad", and river shuttles which will travel from Pripiat to Kyiv.