A new fighter, the American P-51, is proving very effective against the Luftwaffe, and the Nazis want to capture one. So Klink and General Burkhalter host a party for a very important guest - Colonel Hogan - to persuade him to go to England to steal one for them and fly it back in exchange for $1 million and safe conduct to Switzerland. To ensure Hogan's return, a Luftwaffe officer, posing as an American, will accompany him, and his men will be held hostage. Burkhalter also says that there is an efficient Nazi espionage operation in England, and his companion will know how to contact them. Hogan eventually agrees to go, in the hope that he will expose them.
Burkhalter tells Hogan he will be sent to England under pretext of having escaped from Stalag 13. Klink will be the Luftwaffe officer to accompany him, under cover as Major William Davis, KIA (unreported). Hogan radioes Colonel Forbes in London to tell him to expect him on a special mission, but purposely does not give too much information for fear of the spy ring.
Hogan and Klink arrive in England without any problems and their cover story seems to pass. Lieutenant Mills enters their room on pretext of being drunk. He drugs Klink to sleep so Hogan can go and report everything to Colonel Forbes. He tells Forbes that Klink will not tell him the name of the contact, but he is sure Klink will lead him to the contact because they need his help to steal the P-51. So when they leave base to see the contact, Forbes is to put a tail on them. Forbes will arrange a P-51 for them, but Hogan assures him that the Nazis will not get it.
Next morning, Hogan and Klink see a lineup of P-51s outside their window, and Hogan asks Klink to speak to his contact about creating a diversion so they can help themselves. Klink agrees, and the contact is one Mr Brewster (Schindler). Brewster says they have agents and civilian workers planted in RAF Fighter Control headquarters. Hogan tells Brewster to have his agents arrange a scramble order for the following night at 2100 hours. He is also to contact Burkhalter to have him tell the antiaircraft units and Luftwaffe stations not to attack them.
The following morning, Forbes tells Hogan they now have Brewster tagged, and he is leading them to lots of people. They will deal with him when they are ready. The plane, flying suits and parachutes will be waiting for Hogan and Klink. The scramble starts, and Hogan and Klink use its cover to slip away to their plane. Once they are over Germany, Hogan turns off the ignition and pretends they are out of gas, so as to force Klink to bail out with him. The plane is left to crash. When Hogan returns to Stalag 13 and tells his men, they are worried that the Nazis will reverse-engineer the P-51 from the wreckage. He tells them it was a P-51 with a captured Messerschmitt engine in it.