The Three Musketeers (1933)
Tom Wayne rescues Clancy, Renard and Schmidt in the Arabian desert and they join him in going after El Shaitan, a bad guy who is never seen as he tries to wipe out the Foreign Legion
The Shadow of the Eagle (1932)
The Eagle uses sky writing to make threats against a corporation Nathan Gregory owns a traveling fairground and is thought to be the Eagle Craig McCoy is a pilot who goes looking for the Eagle when Gregory turns up missing