Wyatt Earp, Frontier Marshal #38

In "The Hidden Hand," Marshal Wyatt Earp encounters a man named Russ who claims to have ridden with Earp in the mountains and identifies himself as Earp's friend. When Wyatt rides away from the encounter, Russ's true nature is revealed as he pursues Earp with hidden motives. Earp brings the suspect to Dr. Adams in Dodge City for examination, where it becomes clear that the mysterious figure is not who he claims to be. Ultimately, Earp promises to catch the imposter and ensure he receives punishment.