Jim and Buddy decide to follow their pal Tater-bug who left them for another job. No sooner do they arrive than Tater-bug gets shot in the back. Jim suspects Joe Weller but has no proof.
Mysterious deaths have been occurring in the same towns as Miller's Circus and the Governor has sent Ken Kenton to investigate. Ken joins the show but when he realizes that Bargoff is involved, Bargoff has fled and taken Mary Hiller as a hostage. The trail leads to Baron Petroff who concocted the deadly chemical and Ken quickly finds himself the Baron's prisoner.
Bob Merril, looking for the killer of Buddy's father, has found the secret entrance to Pecos' hideout. There he captures Indian Joe who confesses that Marsdan was the killer, But while Bob is off riding in the rodeo his witness escapes.
A boy's father is murdered. As an adult, he tracks down the killers.
