A small river separates Soviet lands from the territory of one of the capitalist powers. On the other side, the girl Pebble lives with her peasant father. One morning, after running after a cow across a river, the girl crossed to the Soviet side. She only spends one day in the kindergarten of the border post, but this day remains in her memory for the rest of her life. Seeing the bright, spacious rooms, the beautiful clothes of the children, delicious plentiful food, and many toys, the girl remembers with bitterness her dilapidated hut, where there is not always bread for dinner. Caressed by the Soviet people, in a new dress, with a bunch of donated toys, Pebble goes back home. A rude shout from a gendarme officer brings the girl back to bitter reality.