A crew from the Terran Colonies, aboard the _Marco Four_, lands on the mysterious planet Arz, where they observe peculiar behavior among the native Arzians, who engage in nightly fishing rituals that end in violent deaths at the hands of predatory creatures. The crew, consisting of navigator Arthur Farrell, commander Lee Stryker, and linguist-ethnologist Gibson, grapples with the enigma of the Arzians' motivations and the absence of any visible means of transportation to the fishing islet. As the crew investigates, they uncover a series of contradictions: the Arzians do not swim, and there are no boats, yet they consistently appear on the islet. Farrell becomes increasingly obsessed with understanding the natives' behavior, leading him to venture into the thorn forest at night, where he discovers sleeping pairs of Arzians. However, he is ambushed and rendered unconscious by an unknown force. When Farrell awakens, he finds himself paralyzed on the islet, surrounded by the very predators he had been observing. He manages to contact Gibson via an audicom, who arrives just in time to rescue him from the impending danger. Gibson reveals that he has discovered an underwater city, suggesting that the Arzians are not the dominant species but rather a form of livestock for the intelligent octopods that inhabit the ocean depths. The crew learns that the octopods have developed a culture that utilizes the Arzians for sport, akin to fishing, where the Arzians are deliberately placed in harm's way to attract the flying lizards. This revelation shifts the crew's understanding of the planet's ecosystem and the role of its inhabitants. Ultimately, the crew realizes that colonization of Arz is impossible under Terran Regulations due to the advanced nature of the octopods, leading them to decide to leave the planet before attracting further attention from its dominant species.
By Roger Dee Aycock · First published 1975 · Genre: Science Fiction, Adventure, Fantasy