Summoned by an Indian princess, Tarzan travels to India where hundreds of wild elephants are in danger. A company is building a hydroelectric dam and the contractors have only a few weeks to finish the job. The building of the dam will flood the valley surrounded by mountains. There is one pass through which the elephant herd can escape but that is being closed. Tarzan comes up against an old nemesis, Bryce, the chief engineer. Bryce undertook a similar dam project in Africa and had a penchant for shooting elephants. It's up to Tarzan to organize the move before Bryce manages to close the pass.
Set in 1869, after the Civil War, Texas had not yet been readmitted to the Union and carpetbaggers, hiding behind the legal protection of the Union Army of occupation, had taken over the state. Federal Captain Porter, a Texan, has to carry out orders against his own people. He brings in the rebel leader Ben Westman whom he knows is innocent of a murder that he is accused of. In trying to prove his innocence, Porter himself becomes a wanted man.
Shiek Yousseff, poses as a friend of the French while secretly plotting to overthrow them. Apposing Yousseff are the Riffs, whose secret leader, The Red Shadow, is Paul Bonnard, a professor who is studying the desert, and whose attacks on the supply trains intended for Yousseff keep the Riff villages in food. Foreign Legion General Birabeau arrives to conduct an investigation, accompanied by his daughter, Margot. Birabeau hires Bonnard to tutor her, and she is attracted to a Legionaire captain, Claud Fontaine. While the general, Bonnard and Fontaine pay a visit to Yousseff, an American newspaper man, Benji Kidd, discovers a secret way in and out of Yousseff's palace, with the aid of Azuri, a dancing girl in love with Bonnard. The latter is forced to resume his role as the Riffs leader, and kidnap Margot until he can convince her of Yousseff's treachery. But Yousseff's men attack the Riff camp and take Margot prisoner.
