Bulldog Drummond goes up against a gang of foreign agents who are members of a British pacifist organisation called "The Key". The agents kidnap an inventor to discover the steal plans for a top-secret robot aircraft.
La petite amie de Drummond est kidnappée par ses ennemis et lui avec son ami Nielsen, un inspecteur de Scotland Yard, suit la piste et tente de la sauver des ravisseurs.
Drummond parvient à empêcher une femme de sauter devant sa voiture mais elle s'enfuit avec sa voiture. Il la retrace et elle lui demande de l'aider à sortir d'une situation dangereuse.
Une compétition entre compagnies de transport par camions va être exacerbée lorsqu'il va s'agir de transporter des pièces d'avion en Californie à temps pour embarquer pour le Japon.
In World War I, Captain Jerry Broun (Lloyd Hughes) feels he has to fight even though the United States has not yet entered the conflict. He enrols in Canada to fly as a pilot, with his adoring young half-brother Mickey (Delmar Watson) wanting to follow in his footsteps by becoming a pilot.
Les cameramen Bob Adams et Elmer "Slug" Davis sont envoyés dans le protectorat britannique de Samari près de la frontière irakienne, avec pour mission d'interviewer le chef arabe Muffadhi. Ils vont se retrouver mêlés à un trafic d'armes et permettre aux troupes britanniques de résister à l'attaque des hommes de Muffadhi.
Two safaris enter the African jungle intent on finding a white girl who is the heiress to a fortune. One safari, led by Jungle Jim, wants to make sure she gets the news that she is now a rich woman and escort her back to civilisation. The leaders of the other safari want to kill the girl so they can try to get hold of her inheritance themselves...
In the Asian province of Seemang where the Bay of Bengal meets the jungle, Chandler Elliott (John St. Polis) owns a large and prosperous rubber plantation. His attractive daughter, Dorothy (Charlotte Henry), is engaged to neighboring planter Tom Banning (William Bakewell) but troubles are brewing for both plantations. When a cargo-load of rubber is shipped on a riverboat to be taken to port, the boat is hi-jacked by river pirates, who the kill the crew and the shipment is stolen. Jim Murphy (LeRoy Mason), Elliott's plantation manager, is plotting with others to force Elliott to sell his plantation. Local explorer Frank Hardy (Frank Buck) determines to find out who is behind the plot.
Bob Carter is a professional soldier of fortune whose expertise is in the use of the machine gun. He has plied his trade for Sun Yat-Sen in the Xinhai Revolution, the Mexican Revolution and with the Spanish in the Rif War for de Rivera. Now he is content to be a Legionnaire in the 20th Marching Company of the 3rd Foreign Infantry Regiment with his comrades in arms the American Muggsy and the Englishman Bilgey.
Carter Snowden (Kenneth Harlan) about to marry Jean McNain (Dorothy Sebastian), is accused of murder. When his accuser is killed, Jean flees the train she is on, and heads into the Canadian woods. Snowden sends a bodyguard to find Jean, who appeals to Captain Jim Down (Frank Hawks) for help. With his friend "Kansas" (Rex Lease) and Indian Luke (Yakima Canutt), Jim hides Jean.
Tex and Stubby keep their promise to a dying friend by helping his partner hang on to his gold mine and to avenge his death by taking on and wiping out a horde of masked riders.