Whispering Smith, a railroad detective, is sent to Medicine Bend to suppress the looting of cars. Smith meets two childhood friends, Murray Sinclair and his wife, Marion. Smith's arrival kindles an old spark of love in Marion's bosom. Sinclair is discharged for looting wrecked cars and Marion leaves her husband when he threatens to ruin the road if he is not put back to work. After trying for weeks to get an interview with Bucks, general manager of the railroad, Murray Sinclair and his followers, Du Sang and Karg, are granted an audience. They state their side of the case. Bucks refuses to put them back to work. He says that McCloud was right in discharging them. Sinclair becomes violent and tries to attack McCloud but is prevented by Whispering Smith. During the scuffle, Du Sang manages to secure a wire that has just been delivered to McCloud. The wire reads: "Notify Dunning Cattle Co. shipment of $65,000 delayed till No. 10 Friday." They decide to hold up the train, get the money, and leave the country. In the Three Horses saloon Sinclair plots to kill McCloud before they hold up the train and Du Sang agrees to do it for him. Tony Wickwire, the Mexican whose life McCloud saved at the Central Mine, walks up behind them and overhears their plan to kill his friend. He shadows Du Sang. Du Sang takes his place at the window of a hotel and waits for McCloud to pass. Wickwire hides behind a lamp post and when Smith and McCloud appear, he warns them in time to save them from Du Sang's bullets. Du Sang thinks McCloud is dead and repairs to a gambling house. Smith, Wickwire and McCloud follow him there. Smith tells him he must leave town or he will "rope him like a cow and drag him down Front Street." The following day Sinclair, Du Sang, Karg and three other followers hold up Number Ten, and kill the messenger. Before he dies, he tells that he recognized Sinclair in the gang. McCloud, notified, starts to the scene of action with the sheriff and a posse. Whispering Smith takes Wickwire, Lloyd and three other men and starts for Williams Cache to head off the bandits there. In the meantime the gang has split into two factions; Sinclair and two followers have decided to leave the country and Du Sang, Karg and Sam have decided to go back to their rendezvous, Williams Cache. Before starting out of the state, Sinclair turns a switch against the relief train which he is sure will be sent out. The train runs into the open switch and crashes through a string of cars on the siding. The posse get out their horses and start in pursuit of the robbers. They finally run them down, but Banks, the sheriff is killed. They return to Medicine Bend with him. Du Sang and his men beat Smith to the cache. Rebstock, who controls the cache, refuses to help Smith run down Du Sang, so Smith and his men start to round up the cattle that have been stolen and hidden there. They clean out the cache and then Smith, Wickwire and Lloyd start after Du Sang. They meet and a fight follows in which Du Sang and Karg are killed and Sam taken prisoner. Lloyd sees Smith thrown from his horse and thinks he is dead, so he rides to Medicine Bend for help. Marion hears him say that Smith is dead. She is carried to her house where she lies ill. Sinclair and his men return to Medicine Bend the same night. Sinclair insists that his wife accompany him out of the country. She refuses. He is about to kill her rather than leave her for Smith, when the doctor arrives and tells him to get away, before the town learns he is there. Sinclair takes his advice. That same evening Smith rides into town with his captives. On his deathbed Banks gives Smith the warrant for Sinclair's arrest and tells him to serve it. After several days of trailing them, Smith and Wickwire came upon them in an arroyo drinking from the stream. They dismount and Wickwire starts to skirt out around to take them on the flank. After Wickwire leaves, Smith shoots and kills two of the men leaving only Sinclair who manages to wound Smith in return. When Smith falls, Sinclair sneaks through the brush and coming upon Smith, tells him he is going to kill him. He reloads his revolver and is about to shoot Smith, when Wickwire reaches a higher spot of ground and sees it all. He draws his revolver and fires at Sinclair killing him before he has pulled the trigger, and Smith's life is saved. When Smith is well enough to travel, he goes to see Marion. They come to an understanding and are married.