London Calling

Song writer Duke Wilson and his showgirl sweetheart Lois Rogers have to keep breaking their engagement because Duke keeps losing his money playing poker...and Lois finally declares finis to the whole process. Duke and his pal, Cliff Dugan, write a new musical comedy and get wealthy playboy Bob Madison to back it, but Madison and Lois are now a romantic item , and his backing-plans includes her as the show's leading lady. Duke and Cliff and Madison are drafted, and Ruth goes along to the camp as an official hostess. Then rookie-newly-arrived Buck Private Duke takes over the U.S. Army and proposes his show be produced at the camp, with Lois as the leading lady. Then Lois finds out that Duke is not doing this just to entertain his fellow rookies, but in order to "test" the show for professional production. Lois declares this to be a selfish move on his part.

Northern Africa, 1943. An Italian corporal receives leave to return home. As he seeks an officer to validate it, a sudden battle traps him in Africa. Just as he succeeds, with the help of a friend, he is captured by the British.

During World War I, an enterprising and patriotic reporter named Jack Bartlett interviews President Woodrow Wilson on the importance of the Fourth Liberty Loan. Jack returns from Washington to find that Otto Crumley, a German sympathizer, has taken control of his newspaper, and when Crumley tears up the story, Jack resigns and joins the Liberty Loan campaign. After raising a large sum of money for the government, Jack succeeds in preventing a strike in a local munitions plant. Later, he learns that Crumley, actually a German agent, has stolen a secret gasoline substitute formula invented by William Desmond, the father of his girlfriend Margaret. Crumley imprisons Margaret, but Jack rescues her and then swims out to the schooner on which Crumley is making his escape. The spy apprehended, Jack turns the ship's guns on a German submarine and sinks it.

Gregory Thorne and Marta Milbanke are engaged. Their fathers are millionaire ship owners. Gregory's efforts to inject a little excitement into their engagement life are fruitless, but when Mr. Milbanke receives an anonymous letter which threatens disaster to his home and fortune if he permits a shipload of supplies for the Allies to leave the docks the young man sees an opportunity for creating what he longs for and tells Mr. Milbanke that he knows who has written the letter but that he will not divulge the man's identity. Gregory, who suspects Count Hilgar Eckstrom, is told that he must terminate his engagement with Marta. But this is what Gregory wants, so he plans to abduct his sweetheart. Gregory's men clash with Eckstrom's gang, who has also come to kidnap Marta, and the disturbance results in the arrival of the police. Marta by mistake, allows herself to be carried off by Eckstrom's men and is taken a prisoner. Gregory, following, is also made a captive, and the young people are held as hostages. How Gregory outwits Eckstrom and places him and his gang in the hands of the law brings about a startling climax.