The film tells about the properties of dust in a playful way. On a dusty rural road, the boy meets a young explorer who invites him to tell him about the dust. The researcher (actor YG Grigoriev) shows the boy images of mineral (inanimate), as exemplified by road dust, and plant dust or pollen, as exemplified by a fireweed flower, under a microscope. They watch the sun go down when the sky turns red from a thick layer of atmospheric dust. Black or yellow smoke comes out of tall industrial pipes - this is poisonous dust in combination with steam. Consequences of the explosion of flour dust at the [flour mill] (a plant for processing grain and producing flour with broken glass and destroyed walls), household dust settling on dark glass. And finally, the Galaxy, in which the space between the stars is filled with cosmic dust. In the physics laboratory, experiments are carried out that illustrate the processes occurring in nature: the coloring of a light beam in red when passing through a curtain of dust, an explosion of flour dust at a certain concentration of air in it and the presence of a spark, the movement of dust particles downward under a microscope, purification of air in the flask from dust using a sound wave.