In the autumn of 1944 in Mattoon, IL a prowler would stalk the town at night, break into their homes and release a toxic gas causing sickness, paralysis, and nausea. More than two dozen separate cases were reported to police over the span of two weeks in Mattoon...but scarce amounts of physical evidence were ever found...causing some to wonder...did this “Mad Gasser” actually exist? Or was this a bizarre case of mass hysteria clouding the entire town?