"Double Trouble" by Carl Jacobi is a science fiction novella published in the mid-20th century. The story revolves around an adventurous journey on Jupiter's Eighth Moon, exploring themes of exploration, communication, and mischief involving peculiar creatures. It showcases a blend of humor and suspense as it follows a group of characters led by the eccentric author Grannie Annie as they navigate a bizarre world filled with strange flora and fauna, culminating in a mystery involving a contagious and hypnotic epidemic. In "Double Trouble," the narrative unfolds as Grannie Annie, a writer known for her vivid imagination, embarks on a quest with her entourage, which includes an old prospector and a Martian illustrator. They set out to investigate an ailment afflicting miners known as "Red Spot Fever," which incites uncontrollable chatter and leads them into the dangerous Baldric region. As they encounter bizarre occurrences, including duplicates of themselves created by intelligent cockatoos, they confront a nefarious plot involving the manipulation of the miners through hypnotic devices. Ultimately, Grannie employs her resourcefulness and cleverness to outsmart the opposition and rescue the affected miners, revealing a tale rich with adventure, peculiar science, and a touch of whimsy. (This is an automatically generated summary.)