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.
Tim McCoy
Bill Carson posing as El Puma
Joyce Bryant
Marian Willis
Ben Corbett
Magpie
Ted Adams
Link Benson
Budd Buster
Old Dobie
Dave O'Brien
Dr. Jerry Leonard
Forrest Taylor
Prof. Lucius Lloyd
Reed Howes
Sheriff
John Elliott
Prospector
Kenne Duncan
Henchman
Herman Hack
Henchman
Chick Hannan
Henchman
Carl Mathews
Henchman Hank
Lew Meehan
El Puma Rider
Kansas Moehring
El Puma Rider
