"The Man Who Killed the World" by Ray Cummings is a science fiction short story published in the early 20th century. The narrative explores themes of power, fear, and the isolation that accompanies absolute control. The story delves into the psyche of Peter Groff, a man who rules through intimidation and greed, illustrating the moral implications of his quest for dominance over humanity. The plot centers around Peter Groff, the epitome of a tyrant whose power stems from his wealth and the fear he instills in others. As he observes a young couple expressing joy despite their poverty, Groff becomes enraged and determines to unleash a devastating weapon that will annihilate the world's population, seeking to demonstrate the extent of his power. However, when he ultimately achieves his goal of becoming the sole survivor in a world devoid of life, Groff is left to confront the hollowness of his victory and the absence of fear that once defined his existence. The story paints a poignant picture of the emptiness that can accompany unbridled power, leaving Groff haunted by the very humanity he sought to destroy. (This is an automatically generated summary.)