"The Sweeper of Loray" by Robert Sheckley is a science fiction novella published in the late 1950s. The story takes place on the primitive planet Loray, where the narrative follows Professor Carver and his assistant, Fred, as they explore the intriguing and dangerous customs of the native inhabitants and their mysterious healing substance known as sersee juice. The novella delves into themes of colonialism, scientific ethics, and the nature of intelligence across species. The plot unfolds as the Earthmen witness startling healing powers attributed to sersee juice, a sacred substance critical to the survival of the Lorayan people. Initially aiming to obtain the juice for scientific examination, tensions rise when Fred resort to violence to acquire it, resulting in devastating consequences for their relationship with the locals. As the story progresses, it becomes evident that the sersee juice has transformative effects, changing Fred into a Lorayan, ultimately leading to a confrontation between scientific ambition and moral responsibility. In a poignant conclusion, Professor Carver chooses to protect his academic reputation over his assistant's humanity, revealing the darker undertones of his character and the implications of his beliefs regarding racial superiority. (This is an automatically generated summary.)