Eetu's family moves from the countryside to the city, where the only natural feature in the neighborhood, a beautiful pond, is in danger of being buried under a planned parking lot. The underwater kingdom of frogs in the pond is threatened with inevitable destruction. Eetu and his friend Konna the frog are also in danger, because Konna has brought a remarkable device from the frog world to the surface, which is immediately noticed by the intelligence services of the world's leading superpowers. The superpowers want to get their hands on this revolutionary technology!