As Jimmy Wakely, Lasses White, Dusty Smith and other members of a medicine show are nearing Big Horn, their final stop of the season, they decide to make camp on land owned by rancher Clem Ferguson. Jimmy and Dusty ride to the Fergusons' to ask permission to camp and arrive just as another rider is dashing away in a fury. They then discover that Clem and his wife have been murdered, the apparent victims of poisoning, and their baby boy, abandoned. Fearing for his safety, Jimmy and Dusty take the baby back to their camp. Unknown to them, they are being watched by outlaws Joe and Slick, who later try to kidnap the baby. Dusty, meanwhile, reports the murders to Sheriff Beasley and learns from the mayor of Big Horn, Melinda Pringle, that earlier that day, she had received a letter from the Fergusons declaring that in the event of their sudden demise, Dr. "Doc" Judd Thomas was to become the baby's guardian. Anxious to keep the baby's whereabouts a secret, Jimmy, who has just arrived in town with Lasses, tells the sheriff that he and Dusty did not see the infant at the Fergusons' house. Upon returning to the Ferguson ranch with the sheriff, Jimmy announces that when he and Dusty first found the Fergusons, their table was set for three, but that one of the place settings has since been removed. Later, Jimmy and Dusty go out to find milk for the baby and end up stealing Melinda's cow. Melinda and her niece Penny witness the theft and follow Jimmy and Dusty to their camp. Melinda is ready to arrest the entire medicine show for kidnapping, but Jimmy persuades her of their innocence and promises to bring the Fergusons' killer to justice. To that end, Jimmy and Dusty return to the Ferguson ranch and there find the third place setting and part of a horseshoe, which they presume belonged to the killer. They also notice new pipes in the yard. Armed with this information, Jimmy and Dusty ride to Big Horn and question Thorpe, the blacksmith, about a horse he is shoeing. After Thorpe insists that the horse belongs to a farmer, he reports Jimmy and Dusty's visit to Doc. Doc, who has hired Slick, Joe, Thorpe and their gang to aid him in a scheme to acquire the Fergusons' oil-rich land, demands that Jimmy and Dusty not be harmed until the baby, whom he needs in order to legally lease the property to the oil company, is found. Jimmy, meanwhile, describes the horse to Penny, who speculates that it belongs to Doc. When they return to the blacksmith's to make a positive identification, however, they discover the horse gone. Jimmy and Dusty spot the horse's tracks and follow them to the gang's hideout, where they steal the horse and take it to Melinda's. Penny, meanwhile, rides to the camp with some toys for the baby, and when she and Lasses spy the sheriff approaching, Penny slips away with the baby after placing a doll in his bassinet. Assuming that the baby is in the bassinet, the sheriff arrests Lasses for kidnapping. At Melinda's, Penny positively identifies the horse as Doc's. Jimmy also shows Melinda a letter he found on the horse, which implicates Doc in the land-grabbing scheme. At that moment, the sheriff, who released Lasses after discovering the doll in the bassinet, arrives and, after finding both the baby and the horse, arrests all of them. Later, Lasses uses the medicine show as a distraction and manages to free Jimmy and Dusty. The two then search Doc's office and locate the empty poison bottle and the lease. Before they can leave, however, Doc and the gang surprise them, and a fierce fight and chase ensues. Jimmy and the medicine show finally overwhelm the gang and turn them over to the sheriff. Later, Jimmy, Lasses and Dusty say a fond farewell to Melinda and Penny, who have assumed care of the baby, and head off with the medicine show.