The Shadow battles a villain known as The Black Tiger, who has the power to make himself invisible and is trying to take over the world with his death ray.

Hopalong Cassidy, boss of the Bar 20 ranch in Texas, rides down the Camino Real in the New Mexico cattle country near Alamogordo, in response to an urgent message from his lifelong sweetheart, Nora Blake, who is in serious trouble. Before he and his saddlemates, "Lucky" Jenkins and "Pappy", can reach her ranch, they are stopped by Clay Allison, a cattle-rustler who is in almost complete control of the district, and wants to extend his holdings by seizing Nora's cattle and driving her out. Seeing Cassidy as a menace to his plans, he has him arrested on a trumped-up charge. Cassidy and his pals shoot their way out of the trouble and reach Nora;s ranch where they learn that Allison's henchmen have murdered her foreman, Tom Dillon, and Allison has sent for a crew of outlaws on the Texas border.

Agadez is a lonely French outpost baking under the desert sun and commanded by the cruel and oppressive Captain Savatt. To it comes, at his own request, Legionnaire Jim Wilson soon followed by his fiancée, Carla Preston, who has been tracing him from post to post. Legionnaires seize the fort and turn Savitt loose in the Arab-haunted desert with only a fraction of the water and food needed to get back to civilization. But Savitt gets through and returns to the fort at the head of an avenging troop of men. But Arabs surround Savitt and his men, and the mutineers, knowing that to leave the fort and aid them means their own death