Saddle Mountain Roundup (1941)

Someone is trying to kill Magpie Harper so he sends for the Range Busters. Crash and Dusty arrive to find him murdered. Then Alibi who was bringing the Range Busters' cattle drive money fails to show up. Dusty accidently finds a secret mine tunnel that leads to Alibi whom he sets free. Returning they see the murderer who flees but Crash is nearby to chase after him.