The first part of the trilogy, about how our fishermen found an underwater portal to ancient Chersonesos." Nobody saw where it came from. However, judging by the sound with which the head came into contact with the side, he was not a ghost. Both swimmers, screaming something inarticulate, rushed to him, and Yurka, leaning over the side, grabbed Seryoga by the shirt collar. Seryoga gawked, his hand on the top of his head. When he saw Bobrov swimming, his face acquired a meaningful expression, and he said almost in a whisper: - Chief, - he said. "That's it!"