Brother and sister Kusti and Iti get lost in a forest while picking strawberries and are captured by an evil forest hag. They are made to work for her. The hag has a son called Bumpy whom Iti befriends. When they get a chance to escape, they decide to take Bumpy with them.

The movie travels through the 20th century by monitoring a steam boiler. We see the history of Estonia through life, agricultural work and people at different times.