The narrator and a companion recount travels to a remote northern region in pursuit of a mysterious gold-field and a string of unexplained disappearances and an epidemic known as the Red Sickness. Their journey ranges from sea passages to overland treks and encounters with local inhabitants as they investigate strange seed-beds and clandestine biological experiments that produce dangerous organisms. The narrative combines adventure, mystery, and survival scenes, building toward a tense escape and a reflective conclusion that links earlier odd episodes in the narrator's life to the revelation of deliberate germ cultivation.