The film opens with the Stooges' mother (played by male actor Monte Collins) attempting to wake up her three boys without success. "Get out of bed you lazy loafers!" she screams to no avail. Finally, she yanks a rope that leads from the kitchen to the bed where the trio is sleeping soundly. This causes the bed to spin vertically until they are expelled.
Marcia Warren (Jeanette MacDonald), while "between pictures" in London hires an American reporter, Homer Smith (Robert Young) as her butler. What Marcia doesn't know is that Smith is an American newspaperman, who strongly suspects that she is a Nazi spy (the real enemy agent is Mrs. Morrison (Mona Barrie).
When he is forced to vacate the office of his debt-ridden correspondence college, 'Professor' Will Davis (Will Hay) goes to the Ministry of International Commerce at Whitehall in order to confront his one-and-only student, PR man Bobby Jessop (John Mills). To get Davis off his back, Jessop proposes to get him a job at Whitehall. Jessop then leaves in order to fetch a Professor Davys at the railway station. The professor is a leading economist who has returned from a long stay in South America in order to advise the British government on a trade treaty with the South American nations, which could be crucial to Britain's war effort.
Faced with mortgage debts, Professor Nathaniel Billings (Boris Karloff) sells his 18th-century tavern to Winnie Layden (Jeff Donnell), who plans to turn it into a hotel. Billings stipulates as a condition of sale that he is able to continue working in a laboratory in the basement. His housekeeper Amelia Jones (Maude Eburne) and hired hand Ebenezer (George McKay) also continue to work in the inn. Layden is initially unaware of the nature of Billings's experiments in the basement laboratory: he is attempting to use electricity to create a race of superhumans to help the war effort. Layden's ex-husband Bill (Larry Parks) is against the sale, but is too late to stop it, and decides to stay on at the inn for a few days.
Karl Wagner dirige un refuge dans le Bowery, un quartier mal famé de New York. Ce refuge est en fait une couverture rempli de pièces secrètes qui lui servent de quartier général pour monter des cambriolages et des hold-up. Wagner ne s’embarrasse d'aucun scrupule, engage des tueurs pour participer à ces casses et n'hésite pas à s'en débarrasser ensuite. L'argent ainsi récolté lui sert à payer les frais de bouche du refuge mais aussi a combler de cadeaux sa femme, car Wagner à une double vie, à la ville il est le professeur Frederick Brenner, éminent psychologue. Alors que la police manque de pistes, tout se complique quand Richard, élève de Brenner et petit ami de Judy, (l'assistante de Wagner) est éconduit par cette dernière. Pour la reconquérir il se déguise en clochard et vient chercher de la soupe dans le refuge, il y croise Wagner et comprend alors que Wagner et Brenner sont la même personne. Wagner n'a plus qu'une solution se débarrasser de Richard. Le lendemain la famille de Richard s'inquiète, téléphone à Judy qui dit l'avoir aperçu au refuge... La police peut alors remonter la piste.
In the midst of World War II, Harvey Leeds, working as secretary for the highly reputed British criminologist Sir Stafford Hart in London, is lobbying for a legislature ordering the immediate arrest of all foreign agents staioned in Britain. Harvey is engaged to Sir Stafford’s daughter, Pamela, and is visiting the Hart mansion. He is about to leave the mansion to be with Pamela, who works at an air raid shelter, when he happens upon a briefcase in the foyer. He looks through the briefcase, that belongs to Sir Stafford’s assistant, Kent Wells, before heading out in the night. he doesn’t get far though, but is knocked out by air raid warden Anton Schugg, and thrown into the back of the warden’s ambulance.
In the pits of Hell, the board of directors decides to replace Satan (Alan Mowbray) with Adolf Hitler (Bobby Watson). Satan persuades them to give him 48 hours to save his job by getting Hitler to perform a single good deed.
Hoping to entertain the military troops stationed in Greenpoint, Mr. Wills organizes the gang into a junior USO troupe. In addition to performing a "boot camp" sketch, the gang participates in a brace of production numbers.