""Hoppy" goes into ACTION against Cattle Rustlers!"
As rustled cattle have mysteriously disappeared, Johnny sends for his friend Hoppy, Hoppy arrives and immediately suspects Dan Slack. Realizing his telegram about Slack was intercepted, he locks up the operator Lafe knowing he can escape. Tailing Lafe he finds a secret entrance to a mine and inside finds the missing cattle. But Slack's men also find him just as the cattle are stampeded through the mine shaft.
Includes: Hop-a-long Cassidy, The Eagle's Brood, Bar 20 Rides Again, Call of the Prairie, Three on the Trail, Heart of the West, Hopalong Cassidy Returns, Trail Dust, Borderland, Hills of Old Wyoming, North of the Rio Grande, Rustlers' Valley, Hopalong Rides Again, Texas Trail, Partners of the Plains, Cassidy of Bar 20, Heart of Arizona, Bar 20 Justice, Pride of the West, In Old Mexico, The Frontiersmen, Sunset Trail, Silver on the Sage, Renegade Trail, Range War, Law of the Pampas, Santa Fe Marshal, The Showdown, Hidden Gold, Stagecoach War, Three Men from Texas, Doomed Caravan, In Old Colorado, Border Vigilantes, Pirates on Horseback, Wide Open Town, Riders of the Timberline, Stick to Your Guns, Twilight on the Trail, Outlaws of the Desert, Secret of the Wastelands, Lost Canyon, Undercover Man, Hoppy Serves a Writ, Border Patrol, Leather Burners, Colt Comrades, Bar 20, False Colors, Riders of the Deadline, Texas Masquerade, Lumberjack, Mystery Man, Forty Thieves, The Devil's Playground, Fool's Gold, Unexpected Guest, Dangerous Venture, The Marauders, Hoppy's Holiday, Silent Conflict, The Dead Don't Dream, Sinister Journey, Borrowed Trouble, False Paradise, Strange Gamble