Join Dr. Calhoun and his loyal pet tormal, Murgatroyd, as they embark on a perilous journey with the Interstellar Medical Service, conducting public health inspections on distant colonial planets. Upon arriving at Tallien Three, they are met with a shocking rocket attack by the Paras‚Aîmutated humans threatening to overtake the ‚Aúnormals.‚Aù While the locals believe they are facing a pandemic of demonic possession, Calhoun suspects a more sinister truth. As he races against time to avoid becoming a Para himself‚Aîor falling victim to their deadly intentions‚Aîhe must uncover the mystery behind this chilling phenomenon. Originally published in the August 1963 edition of Analog Science Fact and Fiction, this gripping tale will keep you on the edge of your seat. (Summary by Gregg Margarite)