Upper class Mrs. Barrington (Jeanne de Casalis) takes in two child evacuees from London, including cocky teenager Ronald (George Cole), lodging them in a cottage she owns. However, it has already been let to annoyingly inquisitive Charles Dimble (Alastair Sim). To compound the confusion, Mrs. Barrington had also agreed to allow it to be converted into a military hospital. Spitfire pilot Flight Lieutenant Perry (John Mills) parachutes into the nearby loch and becomes the first patient, tended by Mrs. Barrington's pretty daughter Helen (Carla Lehmann). Mrs. Barrington moves Ronald to the main house, while Dimble and Perry remain in the cottage.
The film brims with British comedy talent of the period. The Crazy Gang’s mobile fish and chip shop is accidentally tied to a barrage balloon and the gang is carried to Nazi Germany. They are captured but break out of prison, impersonate Adolf Hitler and return to England in a stolen secret weapon.
In the Wołyń Voivodeship in eastern Poland, the German minority is oppressed by the Polish majority. The physician Dr. Thomas does not have any hospital available and his daughter Marie, who teaches at a German school, and needs an important operation, watches when her school is disseized by Polish authorities and demolished by an angry mob. Dr. Thomas protests to the mayor, noting the constitutionally guaranteed minority rights; however his protest falls on deaf ears. Marie and her fiancé, Dr. Fritz Mutius, drive to the provincial capital, in order to put their protest to the Voivode (governor), but they are not even received there either. Deciding to stay in the capital in order to call on the court the next day, that evening they go to the cinema. They are accompanied there by her friend Karl Michalek, who has been pressed into service by the Polish Armed Forces. When they refuse to sing the Polish national anthem Mazurek Dąbrowskiego with the rest of the audience, Fritz gets grievously hurt by the furious Polish crowd. Marie tries to take her betrothed to a hospital, but he is refused admission and succumbs to his injuries.
At the estate of King Herman the 6⅞ (Don Brodie) (a parody of Kaiser Wilhelm II), the deposed king of Moronica, war profiteers Ixnay (Vernon Dent), Amscray (Lynton Brent) and Umpchay (previously Onay) (Bud Jamison) have decided that they have had enough of Moe Hailstone, the fascist dictator they put in power, and want to help Herman retake the throne. To this end, his daughter, the princess Gilda (Mary Ainslee), threatens to try and assassinate Hailstone using an explosive Number 13 pool ball strategically positioned in Hailstone's billiard table. The fictitious country of Moronica (or at least Moe Hailstone) seems to be familiar with a pool game in which the 13 ball is placed at the head of the rack during set up.
Mr. Proudfoot is an attention-seeking bore who subjects his long-suffering wife and exasperated acquaintances to endless tall tales about narrow escapes from bombs. He also teases the local blackout warden for his ridiculous pettiness when it comes to enforcing blackout restrictions.
Eccentric Cambridge archaeologist Horatio Smith (Leslie Howard) takes a group of British and American archaeology students to pre-war Nazi Germany to help in his excavations. His research is supported by the Nazis, since he professes to be looking for evidence of the Aryan origins of German civilisation.
During the Second World War, a German spy goes on the run, carrying important news about a U-Boat campaign. The ship he is travelling aboard is hit by a torpedo. The spy winds up on a lifeboat with other survivors, one of whom is a counterintelligence agent who reveals the German spy's true identity.
The film is set in London during World War II at the time of the Blitz. The leads are a couple of out of work variety entertainers who use great ingenuity in their efforts to get financial assistance to "put on a show". Hoping to put their proposal to the formidable Lady Randall, ex-music hall star Lily Morris, they infiltrate her house in the guise of a servant (Murdoch) and cook (Askey - in drag). After some farcical interludes, they achieve their aim after Lady Randall is persuaded to sing an old music hall standard "Waiting at the Church" at an impromptu show located underground at Aldwych tube station, - used during wartime as an underground bomb shelter. As the ex-music hall star, Lily Morris plays herself. The title of the film is a gentrified version of Arthur Askey's famous catch-phrase - "I thangyew". Also in the film is elderly comic actor Moore Marriott who plays Lady Randall's somewhat eccentric father and the somewhat ubiquitous 'Albert' (Graham Moffatt) who appears under that name in the comedy films of both Will Hay and Arthur Askey.
Most of the story takes place in Switzerland, where Templar interrupts his holiday to retrieve a missing secret code. The key to the mystery is a Swiss music box with a most unusual tune, diligently sought after by enemy agent Rudolph (Cecil Parker) and British secret service operative Valerie (Leueen MacGrath). Templar is aided in his investigation by reporter Mary Langdon (Sally Gray) and Monty Hayward (Arthur Macrae), with Inspector Teal (Gordon McLeod) of Scotland Yard.
The Sea Raiders, a band of foreign agents, led by Carl Tonjes and Elliott Carlton, blow up a freighter on which Billy Adams and Toby Nelson are stowaways, seeking to avoid Brack Warren, a harbor patrol officer assigned to guard a new type of torpedo boat built by Billy's brother, Tom Adams. Intended targets or not, getting blown up does not set well with Billy and Toby and, together with their gang coupled with the members of the Little Tough Guys, they find the Sea Raiders' island hideout, investigate the seacoast underground arsenal of these saboteurs, get blasted from the air, dragged to their doom, become victims of the storm, entombed in a tunnel and even periled by a panther before they don the uniforms of some captured Sea Raiders and board a yacht that serves as headquarters for the Raiders.
Les personnages principaux du film sont des pilotes de deux escadrons de bombardiers en piqué allemands ou Stukas. Le film n'a pas une intrigue stricte, la continuité narrative est brisée entre la vie dans la caserne et le combat aérien. Plusieurs aviateurs meurent et sont honorés par leurs camarades. Cette mort se produit "hors écran" et n'est reproduite que oralement.
New York taxicab driver Malowski (George Tobias) and his cab Betsy enlist in the "First Armored Force" and get caught up in large-scale mechanized maneuvers. The tank featured in the short was the U.S Army's M3 Light Tank known as the Stuart.