"A Toothache on Zenob" by Boyd Ellanby is a science fiction novella published in the late 1950s. The story centers around the character Pehn Karn, an intelligent but physically unattractive young man who battles a recurring toothache. It presents themes of exploration, communication with extraterrestrial beings, and the clash between progressive thought and traditional beliefs within a unique alien culture. The plot unfolds as Pehn and his friend Nautunal intercept signals from a distant planet in a neighboring solar system, potentially indicating intelligent life. As they decipher the mathematical patterns in the signals, they realize the signals are a means to communicate with extraterrestrials from a planet orbiting the star Topaz. Despite his worsening toothache and familial pressures, Pehn seeks out his friend Bidagha, a progressive Healer, to understand the mysterious signals better. Tension arises between the scientific aspirations of Pehn and Bidagha and the conservative views of Pehn's father, the Premier. The climax occurs during a ceremony in a sacred cave, where Bidagha attempts to use modern tools to heal Pehn, leading to tragic consequences as the cave collapses, sealing both Pehn and Bidagha within. Ultimately, the story examines the consequences of rejecting scientific progress in favor of tradition. (This is an automatically generated summary.)