The 57th of Republic's 66 serials is filled with stock footage from some of that company's previous "Zorro" serials, primarily 1944's "Zorro's Black Whip", so a lot of the footage finds Ken Curtis wearing the same costume as Linda Stirling and (mostly) her double Babe DeFreest wore in that serial. Disney now owned the rights to the Zorro character, but Republic wasn't about to let all that footage go to waste when all they had to do was create a character called Don Daredevil. Those who express surprise at finding TV's "Festus" as the lead in a serial evidently are looking at the career of Ken Curtis from the back end rather than from the beginning aspect of his career. The serial has political boss Douglas Stratton (Roy Barcroft) finding that an old Spanish Land Grant made to Ricardo Moreno and later sold to Patrick Doyle to be a forgery, and he tries to cash in by having his men attempt to stake out mineral claims and homesteads on the ranches now part of the original grant. The plot is resisted by Patricia Doyle (Aline Towne), grand-daughter of Patrick Doyle, and her neighbor Gary Taylor (Robert Einer). Stratton backs up his demands with the help of the crooked sheriff (I. Stanford Jolley), and Gary and Patricia are facing with losing their property when her cousin, Lee Hadley (Ken Curtis), arrives from back East. Foreseeing Stratton's move, he already has homesteaded the Doyle Ranch, forcing Stratton to temporarily back down. The other ranchers follow suit, homesteading and mineral-claiming their own property, but Stratton organizes a gang of night riders to try and drive off the ranchers before they can prove their titles. Lee decides to take on the character of Don Daredevil, which has been used by his grandfather during earlier times of trouble. As the masked daredevil, Lee is successful in driving off Stratton's raiders. Stratton lures Don Daredevil into an ambush but he escapes to an old ore shack overhanging a cliff, and Chapter One, "Return of the Don", ends when the shack is dynamited. Eleven more chapters reel by before Lee/Don Daredevil acquires the original, unforged deed and puts an end to Stratton's scheme in the 12th episode, "Flames of Vengeance."