In the late summer of 1944, a paralyzing terror gripped the small town of Mattoon, Illinois. Residents began reporting a mysterious prowler who sprayed a sweet-smelling, paralyzing gas through their open bedroom windows in the dead of night. Victims described sudden nausea, temporary paralysis, and a lingering metallic taste. As sensationalized newspaper headlines amplified the story, the reports skyrocketed. However, despite massive police manhunts and armed citizen patrols, no physical evidence of a gas-wielding attacker was ever found. Modern psychologists and historians now recognize the "Mad Gasser of Mattoon" as one of the most perfectly documented cases of mass psychogenic illness in American history. The toxic gas was not a chemical weapon, but a psychological contagion, fueled by wartime anxiety, industrial pollution from local factories, and irresponsible yellow journalism. This book explores the terrifying power of collective delusion. You will examine the neurological mechanics of psychogenic physical symptoms, the reckless role of the media in validating paranoia, and the desperate societal need for a tangible enemy during a period of intense global stress. Breathe in the toxic atmosphere of a panicked town. Learn how the human mind can conjure genuine physical symptoms from the sheer terror of an invisible threat.