When the fisher master Alemi took little Raidis fishing, they did not yet know that what happened to them would be the beginning of a new chapter in the history of Pern. Suddenly the sky turned black and a strong wind arose, which caught and smashed their boat. But they were saved - strange fish swam up from the depths, held them above the water and carried them back to the ground, and on top of everything talked to them. Alemi turned to the vast knowledge of AIVAS for help and learned that these strange fish were dolphins - brought to Pern by colonists to help people explore the ocean of the new planet. Now they need to restore all knowledge about them...