A German shepherd named Queenie kills and steals foxes from fur ranches. The dog was trained for the grisly task by her outlaw owners, Pete and Brad, who hope to make a fortune by selling the hot pelts. Agent Don Howard and his canine partner, Rin Tin Tin, are sent to investigate, but their work is jeopardized when Rinty is mistakenly identified as the four-legged fox-slayer and targeted for death.Rin Tin Tin Jr. took over his heroic predecessor's adventure roles after the original Rinty died in 1932.Rinty Jr. starred in 13 pictures, his final appearance opposite Don Ameche in 1939's Hollywood Cavalcade. Dennis Moore appeared in over 200 films and TV shows, most notably East Side Kids (1940), Spooks Run Wild (1941) and The Mummy's Curse (1944). Mae Busch is probably best remembered for her appearance in several classic Laurel and Hardy comedies.