Saddle Mountain Roundup

Elderly rancher "Magpie" Harper is suspicious that all his workers, including Chinese cook Fang Way, are cheating him. Magpie has formed a partnership with his neighbor, Henderson, whose daughter Nancy he considers family. One night, at the Harper ranch, Magpie tells Henderson that he will not honor the partnership until his lawyer, Dan Freeman, finalizes the contract. Henderson suspects that Magpie's foreman, Blackie, has been stealing from Magpie's herds during the Saddle Mountain roundup, because he complained when Magpie assigned the lawmen known as The Range Busters to guard the herd on its way to the stockyards. When Blackie comes in, he and Henderson start arguing over Henderson's accusations. The Range Busters, "Crash" Corrigan, "Dusty" King and "Alibi" Terhune, meanwhile, are guarding Magpie's horses until they can be sold, but when they get a note from Magpie asking them to hurry back, Crash and Dusty leave Alibi to collect the money. After he discovers that he has been poisoned, Magpie writes a note to The Range Busters, warning them that someone is trying to rob him. Before he can write the location of his hidden money, however, he is shot and killed. Fang Way finds Magpie's body and pockets the note before Blackie sees it. Crash and Dusty then are ambushed on their way to the ranch, but after escaping their attackers, they arrive and learn about Magpie's murder. The sheriff questions Blackie and learns about Magpie's argument with Henderson, but the sheriff is more interested in fishing than investigating the crime. When lawyer Dan arrives, Blackie tells him that Henderson is a suspect, and Blackie searches Dan's briefcase without his knowing. During a discussion about Magpie's will, Dan reveals that Magpie left no money in the bank, but Crash and Dusty assure him that Alibi is taking a secret route to the ranch to avoid thieves. While Dusty flirts with Nancy at her ranch, Crash, who also is vying for Nancy's affection, follows Fang Way to the Henderson ranch. Crash stops Fang Way and discovers a note from Magpie in Fang Way's egg basket, advising Nancy that he has left another note for The Range Busters, but Fang Way feigns ignorance. Alibi then is kidnapped on his way to the ranch and, when the robbers are unable to find the $10,000 he has collected for selling Magpie's herd, they take him to a remote cabin. Crash and Dusty finally get Magpie's note from Fang Way, who kept it merely because he was frightened. When Alibi does not arrive as expected, Crash rides out to look for him, while Dusty pokes around Magpie's house and is knocked unconscious when he falls through a secret trapdoor. Crash returns without having found Alibi, and now discovers that both Dusty and Blackie are missing. Dusty awakens in a mine tunnel beneath the ranch house, and follows the tunnel until he hears voices. Through a wooden wall, Dusty hears a guard threatening Alibi, and scares off the guard by pretending he is Magpie's ghost. Dusty goes through a secret door to free Alibi, while Crash, again looking for his friends, finds Blackie's body in a remote cabin. Dusty and Alibi encounter a mysterious intruder in the tunnel and follow him to the ranch house, where Crash then returns and finds Fang Way unconscious. When the man runs out of the house, Crash follows him. Dusty and Alibi join in the pursuit, and Crash captures the man, who is revealed to be Dan. Later, Henderson tells everyone that he learned that Dan had discovered Magpie's money in the secret tunnel. When Blackie searched his briefcase, he found evidence that Dan had a criminal record for embezzlement, and blackmailed him. With the murderer behind bars, The Range Busters leave for Denver to buy a new wig and hat for Alibi's ventriloquist's dummy, Elmer, who lost his during the kidnapping.