Dr. Calhoun and his pet Tormal Murgatroyd work at the Interstellar Medical Service, conducting regular public health checks on vast colonial planets. When they reach Talien Three, they are met by the Parasov missile attack, a mutated human form that quickly replaces the "normals." Normal people think this is a pandemic of demonic possession, but Calhoun has his doubts. If he may not become a Para or be killed by them, he simply can understand it.
