The main heroes of the tale - Horse and Frog - are bored with their native home on Earth. "Let's travel where the grass is greener, the water is wetter, the sun is hotter," the friends decide and set out on a space trip through the universe. On an extraordinary journey, the Horse and the Frog are waiting for meetings with the Earth's satellite the Moon, the planets orbiting the Sun and their rulers - the story writer Mercury, the gentle and patronizing but burning Venus, the warlike Mars, the majestic Jupiter, the guardian of time Saturn, the strange inventor Uranus, the watery Neptune, cosmic chef Pluto. After traveling through the vastness of the universe, the friends are convinced that the most beautiful and expensive home planet is Earth.