Body Snatchers - The body snatchers: corpse and effect - University of Cambridge : Stevenson uses the grisly trade to explore themes of moral decay, the "shattering" of a man's conscience, and the chilling realization that scientific progress can sometimes come at a horrific human cost. 3. Science Fiction: Invasion of the Body Snatchers Body Snatchers : The story follows a medical student named Fettes who is tasked with receiving bodies for his professor. He eventually recognizes one of the "donations" as a man named Gray, whom he had seen alive and well just hours before. The body snatchers: corpse and effect - University