In the last of three serials that John Wayne did making his bones in B picture Hollywood, he does what is described as a modern adaption of Alexander Dumas's classic The Three Musketeers. Any resemblance to that novel and this film is completely coincidental.
Wayne is an American pilot who is flying in North Africa and saves Jack Mulhall, Francis X. Bushman, Jr. and Raymond Hatton, Foreign Legionaires, from certain death by machine gunning from the air an attacking Berber tribe. The group of them strike up a great friendship and the three decide to call themselves The Three Musketeers and adopt Wayne as their D'Artagnan.
The Duke with that little action apparently messed up a planned revolution against the colonial occupiers so the would be revolutionaries frame him for gun running and later murder. It takes twelve chapters for Wayne to clear himself and unmask the mysterious masked leader of the Devil's Circle conspiracy, El Shaitan.
In the mess of a film where not one of the white dudes speak with any kind of an accent including the multi-national Foreign Legionaires, you can see elements of The Desert Song, Gunga Din, and Beau Geste. But other than the title not a hint of The Three Musketeers.
Lon Chaney, Jr. and Noah Beery, Jr. both make brief appearances in The Three Musketeers and both get killed early on in the serial. I'm sure neither of them counted this serial as anything they talked up in reminiscing about their careers.
Only confirmed and solid fans of John Wayne should watch this film. I can safely say that Alexander Dumas's spirit becomes most restless when this film is shown.