Based on the philosophical fairy tale “Dandelion Boy and Three Keys” by Alexander Sharov about the meaning of life and about the boy to whom the gnomes gave three keys. He had to manage them correctly and open the right lock.
Bolshevik Mravin, under the name of engineer Pyotr Ivanovich Lednev, risking his life, takes V.I. Lenin’s “Letter to the American Workers” to America. With the help of John Reed, he publishes it in one of the newspapers.
Kris Kelvin joins the space station orbiting the planet Solaris, only to find its two crew members plagued by "phantoms," creations of Solaris. Kelvin is soon confronted with his own phantom, taking the shape of his dead wife Hari.
The events take place in Russia in 1917. A former peasant, and now a soldier, Ivan Shadrin, was sent by fellow soldiers from the German front to revolutionary Petrograd to hand Lenin a letter with questions from his comrades.