The exploits of five World War II prisoners in a German POW camp, 'Stalag 13' who, while "under the cover" of being typical prisoners of war, are really secretly doing their utmost to sabotage the German war effort through whatever means necessary. Col. Klink is very proud that no prisoner has ever escaped under his watch, not that they would want to. Suave, cool and smart, Col. Hogan takes advantage of Col. Klink and Sgt. Schultz's bravado and general cluelessness to carry out his missions.
A German oil refinery is so heavily protected that allied bombers have been unable to destroy it. So Colonel Hogan decides that the only way to fool the gunners is to use a German plane—and he makes plans to hijack one!
When the hapless Colonel Klink reluctantly joins two other German prison camp commandants in a plot to discredit General Burkhalter, all three men are subsequently arrested. Hogan and the gang must act quickly to keep their clueless commandant in charge of Stalag 13.
After being double-crossed by a female lure, Hogan and his men are confronted by a Gestapo agent who knows all about their secret operation and demands "hush" money --- in the form of a million dollars in diamonds!
Hogan is unexpectedly drawn into an assassination plot against Adolf Hitler when he is ordered to deliver a briefcase rigged with explosives to a German general involved in the plot.
Two German officers have new and differing plans for Stalag 13 --- both of which threaten Hogan's operations. In order to protect the camp and the gang's secret subterfuge, Hogan plays the two men against each other.
Hogan is stymied over how to rescue a captured member of the underground until a potential diversion --- in the form of an old World War I buddy of Sergeant Schultz --- arrives at Stalag 13.
Hogan manages to free four underground leaders from the Germans and smuggles the quartet into Stalag 13. But a plan to spirit the men off to freedom in England suddenly looks hopeless when a leaky pipe fills the gang's emergency tunnel with water!
All goes well when Hogan's gang steals Klink's code book from his safe, photographs the contents, and returns it to its proper place. But there's a small hitch --- Carter forgot to load the camera with film!
When Newkirk discovers a new radio controlled tank that could win the war for Germany, the allies want Hogan and the men to photograph the tank and then destroy it --- but complication ensue during their mission.
In the first of a two-part story, "Tiger," a female underground agent, is arrested while trying to document some secret German bases and is held in Paris for questioning. So Hogan and LeBeau become stowaways aboard Klink's staff car and head for Paris to free her.
Part 2 of 2. While trying to free the underground agent "Tiger" in Paris, Hogan must seek help from a Parisian fortune teller and also enlist the aid of a man who is a look-alike for Nazi Police Chief Heinrich Himmler.
With camp security raised, Hogan and his men are desperate to smuggle some top-secret photos of German fortifications to the allies. The solution? Make liberal use of Carter's remarkable impersonation of Adolf Hitler.
The aristocratic Colonel Klink fails a routine physical exam and lands a combat assignment at the Russian front! Fearing a hard-line replacement at Stalag 13, the men must do all they can to rescind Klink's marching papers.
Hogan and his men make plans to lure Luftwaffe bombers within range of an allied anti-aircraft installation hidden in an abandoned warehouse, but Carter make a shamble of the plan when, while "leaking" the info to Klink, he forgets the name of the town where the strategic warehouse is located.
Suspecting a security leak at Stalag 13, General Burkhalter goes fishing with some false information and Colonel Hogan falls for the bait. As a result, Burkhalter plants a spy among the prisoners to expose the guilty parties.
An assertive General Burkhalter "requisitions" the famous Édouard Manet painting, "The Fife Player," from the Louvre museum in Paris to give to Hermann Goering as a birthday present. Undaunted by the seeming impossible logistics, Hogan and LeBeau decide to steal it back!
Colonel Hogan is less the thrilled when he is assigned to help an obnoxious American general flee Stalag 13 --- and the secret escape plan, involving a prisoner swap, winds up as trying and difficult as the arrogant escapee himself.
When the gang's hidden cache of money --- needed to purchase a secret map --- goes up in smoke, the men of Stalag 13 must come up with a way to replace the cash --- and decide to pull off a bank heist in the nearby town.
Hogan and his men are determined to create chaos during some staged war games a ruthless Nazi colonel has scheduled near Stalag 13. So what do you suppose would happen if the fake explosives planned for the exercises were somehow replaced with live ammunition?
Hogan nixes a mission to destroy a synthetic fuel plant because the caper is too risky....but he is overruled -- and forced to participate in the scheme by the ploy's mastermind, a strong-willed, determined female scientist.
Masquerading as German workers, Hogan and the crew have made elaborate and foolproof plans to blow a German cannon factory sky-high --- but their plan backfires when Newkirk winds up being drafted into the German army!
When an important Gestapo official wants to defect, Hogan brings him to Stalag 13 --- and convinces Colonel Klink that the fugitive is Adolf Hitler in disguise... who is trying to elude assassins by hiding at the camp!
Captain Kurtz, General Burkhalter's brother-in-law, becomes the camp's tough new adjutant. What's worse he's keeping a watchful eye on every corner of Stalag 13 and ends up getting in the way of Hogan's plans to blow up an enemy munitions train.
The bumbling Sergent Schultz has unwittingly been conned into making a trip to Heidelberg as courier for the underground, but after upsetting Colonel Klink, the sergeant is ordered to remain grounded at the camp. How will Hogan and the gang win him a new weekend pass?
When a French flier is captured, the Nazis verbally malign the man's fiancee in an attempt to get him to reveal important information. To keep him from cracking under the interrogation, Hogan smuggle the man's girlfriend into the stalag and arranges for the two to be married.
Colonel Klink's "no escape" record is jeopardized when Malcolm Flood, a British escape artist, lands in Stalag 13 and intends to continue his impressive escape record --- a plan likely to endanger Colonel Hogan's scheduled rendezvous with an OSS agent.
When the Nazis construct a new communication tower near Stalag 13 -- one that is potentially deadly to the allies -- Hogan enlists a beautiful underground agent to help destroy the tower, with Kinchloe assigned to snap some incriminating photos of General Burkhalter.
After receiving a "poor' rating from the Inspector General of prison camps, Colonel Klink brings in a stern new sergeant to discipline the prisoners. How can Hogan and his men make sure the camp's ruthless "discipline machine" has the shortest reign possible?
A secret military document is mistakenly hidden in Colonel Klink's topcoat at a party, and a desperate Hogan must nab the document because of both its value to the allies and because Klink will be charged with treason and replaced at Stalag 13 if it is discovered in his possession.
Klink becomes convinced that he is marked for assassination by a mysterious "Mr. X" after a series of close calls at the stalag. Could Hogan be behind the threats? Yes... but it's all part of a plan to masquerade as Klink in order to help a valuable underground agent escape from the camp!