This World Is Taboo by Murray Leinster, Science Fiction, Adventure 12+

📘 Written by Murray Leinster (a pseudonym of William Fitzgerald Jenkins's) This World Is Taboo was first published as "Pariah Planet" in Amazing Stories, July 1961, and is the second volume in the Med Services series. Leinster wrote more than 1500 stories and articles during his career and is credited with first using the concept of parallel universes in his fiction.