The narrative unfolds in a vast universe where humanity, despite its insignificance, has developed advanced space travel capabilities. However, a seemingly innocuous molecular change on a distant planet leads to the emergence of a deadly virus known as chlorophage, which threatens all life forms. The story begins aboard a large space liner, where the ship's doctor, Nordenfeld, is tasked with ensuring the health of passengers as they embark on a journey from Altaira to Cassim. As passengers board, the doctor scrutinizes them, aware of the potential dangers posed by the virus. Among the passengers is a young girl, Kathy Brand, who has been isolated in a sterile environment on the planet Kamerun, where her father, a microbiologist, fought to protect her from the virus. After a harrowing escape, he sacrifices himself to ensure her safety, sending her to Altaira just before he dives into the sun. Nordenfeld, upon learning of Kathy's background, becomes increasingly concerned about the implications of her presence on the ship. He isolates her in the hospital compartment, conducting tests to determine if she carries the virus. As the ship travels, he discovers that the chlorophage has indeed infected the ship's air supply, leading to a race against time to contain the outbreak. Tensions rise as the crew grapples with the reality of a potential pandemic. The doctor realizes that the only way to save the ship and its passengers is to return to Altaira and implement a quarantine. He devises a plan to use a newly discovered microorganism from the botanical specimens aboard the ship, which appears to consume the chlorophage, as a means to combat the virus. As the story progresses, the crew must confront the moral implications of their actions, weighing the lives of the passengers against the potential for a catastrophic outbreak. Ultimately, Nordenfeld's determination to protect humanity leads to a solution that could save countless lives, but not without significant sacrifice and ethical dilemmas. The narrative explores themes of survival, the fragility of life, and the responsibilities that come with scientific advancement. It poses questions about the lengths to which individuals will go to protect others and the unforeseen consequences of their actions in the face of a deadly threat. The resolution brings a glimmer of hope as the crew prepares to return to Altaira, armed with the knowledge and tools to combat the virus, while also acknowledging the heavy toll of their journey.
By Murray Leinster · First published 1957 · Genre: Science Fiction, Medical Thriller, Adventure