Singing cowboy Gene Autry and his faithful sidekick Frog Millhouse (Smiley Burnette) go undercover as wandering troubadours in this musical Western with a touch of mystery. Their mission is to find the villain who killed a half-blind old man named Frank Martin for his gold. But the only clues they have are a guitar string and a stray horse. Meanwhile, the dead man's granddaughter (Barbara Pepper) grows suspicious of their motives.