The Fighting Renegade (1939)

El Puma a Mexican desert guide escorts an archaeological expedition headed by Professor Lucius Lloyd through the Indian badlands of Mexico Marian the professors 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 Marians father was slain The reluctant Magpie believes that his old pal is guilty Carson sets out to prove otherwise