British Captain Terence Stevenson (Robert Donat) accepts an assignment even more dangerous than his everyday wartime job of defusing unexploded bombs. Fluent in Romanian and German and having studied chemical engineering, he is parachuted into Romania to assume the identity of Captain Jan Tartu, a member of the fascist Iron Guard. He makes his way to Czechoslovakia to steal the formula of a new Nazi poison gas and sabotage the chemical plant where it is being manufactured.
After Japanese spies from the infamous Black Dragon Society infiltrate United States borders, Federal Agent Rex Bennett is enlisted by the government to capture them. As Oyama Haruchi, leader of the dangerous paramilitary group, begins to destabilize the United States war effort through sabotage and corruption, Bennett must team up with British special agent Vivian Marsh and Chinese special agent Chang Sing to stop them and help win the war.
In the The Masked Marvel, a hero dressed in a business suit and a face mask fights the Japanese saboteur Sakima and his espionage organization. The hook of the story is that, in a reversal of the common serial "Masked Mystery Villain" stock character, the audience doesn't know who the hero is until the final reel - all the audience is told is that The Masked Marvel is one of a group of special investigators (the same plotline is used in the Republic serial The Lone Ranger).
Michael Lanyard (Warren William), the Lone Wolf, agrees to go to Alexandria to help the Allied cause during World War II. There, he and his valet, Llewellyn Jameson (Eric Blore), are met by his old friend, nightclub owner Johnny Booth (Sheldon Leonard).
In an attempt to control the entire Middle East and defeat the Allies, Nazi agent Baron von Rommler (Lionel Royce) captures and impersonates Sultan Abou Ben Ali (also Lionel Royce), leader of all the Arabs. Opposed to him is Secret Service Agent Rex Bennett (Rod Cameron), along with British reporter Janet Blake (Joan Marsh) and Chief of Police Captain Pierre LaSalle (Duncan Renaldo).
Erich Kohler (Portman), a crack Luftwaffe pilot who speaks fluent English, is instructed by his superiors to drop a cargo of bombs on the Belgian city of Ghent and then to bale out of his plane wearing a British RAF uniform, gain the confidence of the local populace and then try to convince them that the British are responsible for the bombing of civilian targets in Belgium. The plan goes awry when he falls into the hands of the Belgian Resistance, who believe they are doing him a favour by arranging for him to be smuggled to Britain among a group of downed RAF pilots who are being returned that night.
During World War II, with shipping being sunk by submarines and with an American scientist working on radio technology killed by Nazi spies, FBI agent G. B. Fleming (Roger Pryor) comes up with a plan to catch the Nazis. He believes that radio signals are alerting the Germans about ship movements. His plan is to fire all the local radio specialists, who likely will seek any employment, including working with the enemy. Tailing the jobless radio men will help the FBI find the Nazis.
In 1938, refugee Peter Vadassy (James Mason) decides to take a vacation at the Hotel Reserve to celebrate both his completion of medical school and his impending French citizenship. When he goes to pick up some photographs at the local pharmacy, he is taken away and questioned by Michel Beghin (Julien Mitchell) of French naval intelligence. When his negatives had been developed, some of them turned out to be of French military installations. It is discovered that while the camera is the same make as Peter's, the serial number is different. Peter is released on condition that he find out which other hotel guests have cameras like his.
Eileen Carr, dans un cauchemar, voit l'assassinat d'un homme. À son cri, ses voisins accourent et l'un d'eux est justement l'homme assassiné. En fait, Barry Malcolm est un agent secret, luttant contre l'extension nazie. Paul Devon lui confie une mission pour porter un message à Hong Kong. Eileen et lui se sentent attirés l'un vers l'autre. Mais, soudain, le rêve d'Eileen devient réalité...
Nazi spies, led by the mysterious "Master Key", kidnap Professor Henderson in order to acquire his "Orotron machine" which is capable of extracting gold from sea water. FBI agent Tom Brant, aided by reporter Janet Lowe and Detective Lt. Jack Ryan, attempt to rescue him and crack the Nazi spy ring.
On a neutral island in the Pacific called Shadow Island (above the island of Formosa), run by American gangster Lucky Kamber, both sides in World War II attempt to control the secret of element 722, which can be used to create cheap aviation fuel.
L'action se déroule pendant la Seconde Guerre mondiale. Un chercheur italien qui a découvert la formule de la bombe atomique est aux mains des Allemands. Un espion américain fait tout pour le délivrer.