Pik is a Martian creature who looks sort of human except for his turtle-like face. On an expedition to the mountains to gather singing stones, he finds a strange crystal. He brings it home and discovers that it's an egg. The egg hatches out as a baby ""flying thing""--part bird, part airplane, and much bigger than Pik. Later Pik and the hatchling, named Airi, return to the mountain, meet other flying things who welcome Airi home, and stay on there with Pik as fond Hatch-master. This nonsensical fancy about friendship or whatever is told in prose and fine-line drawings as cold and inhospitable as the Martian setting.