Brittany Barbieri explores The Mad Gasser of Mattoon, a mysterious 1944 case in Mattoon, Illinois. Residents reported a strange, pleasant-smelling gas that caused paralysis, burning throats, and blurred vision, along with sightings of a shadowy figure outside their homes. Despite police investigations, no evidence was ever found. Brittany examines theories ranging from mass hysteria and industrial pollution to possible secret government chemical experiments linked to World War II. The case remains unsolved, leaving its true cause unknown. She encourages listeners to research primary sources and continue questioning the unexplained.