Jim Vaus, U.S. Army electronics expert becomes involved with gangsters. His wife begs him to quit but he's become too useful, discovering wiretaps, setting up alarm systems and even saving a mobster's life by diffusing a time bomb. Gang-member Tony urges Jim to invent a device to tap lines carrying race results and delay them so they could make big money on post-race betting. After Tony is killed by a fellow mobster, Alice persuades Jim to attend a tent meeting held by evangelist Billy Graham.