"Last Enemy" by H. Beam Piper is a science fiction short story published in 1950. In a world where reincarnation is scientifically proven, researcher Hadron Dalla's experiments threaten to upend society's political order. When she mysteriously disappears, Paratime Police operative Verkan Vall must find her before hostile forces silence her permanently. But Dalla's discoveries about consciousness and death carry dangerous implications that extend far beyond one timeline—revelations that could expose secrets meant to remain hidden forever. (This is an automatically generated summary.)