Many years have passed since the founding of the colony of earthlings on Astra. Several generations of colonists changed. People have changed in appearance, they have new abilities, habits and character traits have changed. Something is lost, and something is gained. The young colonist Dalgard Nordis with his knife brother from the water people of Ssuri makes a test journey before his initiation into adults. Meanwhile, a ship of earthlings lands on Astra. The crew is unaware of the existence of an earthly colony on the planet. On the planet, in addition to the Vodyani people, there is another intelligent race, with whom the Vodyans have a long-standing and irreconcilable enmity. In ancient times, this race, with its internal strife, almost brought to destruction all life on the planet, including themselves. It is with their representatives that the crew members of the earthly ship meet and essentially become their honorary guests-prisoners...