El Puma, a Mexican desert guide, escorts an archaeological expedition headed by Professor Lucius Lloyd through the Indian badlands of Mexico. Marian, the professor's niece accompanies the party as only she can translate the Aztec writings in the diary of her father, murdered on a similar expedition six years previous. The professor is murdered by a knife, and the weapon is recognized as the property of El Puma. Magpie, a Federal Investigator, knows that El Puma is really "Lightnin' Bill' Carson, a former federal agent who has been missing since Marian's father was slain. The reluctant Magpie believes that his old pal is guilty. Carson sets out to prove otherwise.
as Bill Carson posing as El Puma
as Marian Willis
as Magpie
as Link Benson
as Old Dobie
as Dr. Jerry Leonard
as Prof. Lucius Lloyd
as Sheriff
as Prospector
as Henchman
as Henchman
as Henchman
as Henchman Hank
as El Puma Rider
as El Puma Rider
as El Puma Rider Pedro
as Henchman
as El Puma Rider from Argentina (uncredited)
as Stagecoach Driver
as Wagon Driver
as Henchman
