This is a poetic film set in the times of Lenin's NEP. A ballet dancer steals a brooch and gives it as a present to another dancer. This is a crime of passion. A mysterious black ball is after the heroine. She runs away from it and manages to give the brooch in an exquisite pirouette movement, as shiny as diamond facets. What gives a stone its dazzling luster are its polished facets. But the real gem is love, and it's much harder to get than any diamond in the world.

Srubov is a part of CHEKA, the secret police Lenin established after the Bolshevik Revolution. They arrest, interview for a minute, try in ten seconds, and execute intellectuals, aristocrats, Jews, clergy, and their families. In the building basement, five people at a time are shot as they stand naked facing wooden doors. No one to remember their last words; no martyrs, just anonymous bodies. Daily, the kangaroo court, the executions, the loading of bodies onto wagons. Srubov is cold, distant, sexually dysfunctional, and a deep thinker, hated by former friends and his family. As he tries to reason the nature of revolution and the purpose of CHEKA, he slowly goes mad.

A regular military call-up. Young guys, having got call-up papers and having passed a medical board checkup, enjoy themselves and spend the last days of freedom in different ways: some in discotheques, some in a company of friends outdoors, others are even carousing and scuffling. A colonel Nikitin (Yu. Nazarov) with a group of officers is ordered to accompany conscripts future marines - in a special train to the military service place, situated in the Far East. The whole trip takes several days. Right here, in the train wagons, with no dads and moms round, young conscripts are in for showing their worth and gaining their first experience of real army life.