Hogan is meeting a rendezvous with Underground agent Gretchen Klemens. Gretchen tells Hogan that Field Marshal Rudolf Richter wants to defect to England and negotiate a separate peace (something Hogan doubts very much will succeed). On Thursday he will be coming to Stalag 13 on prextext of a military installation inspection tour and Gretchen is posing as his secretary. Once there, Hogan and Co will take over and smuggle him to England. Hogan refuses; Richter is a well-known figure whose face is instantly recognisable to any German, which would make him a difficult escapee. But a little love-making to Gretchen (to cover up when a patrol approaches) changes his mind.
Richter and Gretchen show up at Stalag 13, but earlier than expected, so their escape is not ready. In order to find out the reason for the change in schedule, Hogan goes over to Klink's office under pretext of offering Le Beau's culinary skills for a dinner. He is invited to the dinner.
The dinner is interrupted when Major Hochstetter of the Gestapo arrives. Hochstetter calls Klink out to his office, under pretext that there has been an escape from Stalag 4. Once alone, Richter explains to Hogan that they moved up the deadline because the Gestapo is closing in on him. Hogan realises why Hochstetter is at Stalag 13 and has to make his move before Hochstetter does. So, under pretext of taking a walk, Richter is to come to barracks 2. They kit him out in a GI uniform and hide him in the one place Hochstetter is guaranteed not to look when he starts searching - the cooler.
Meanwhile, Hochstetter tells Klink that he has orders from Hitler and Himmler to keep Richter under surveillance as he is suspected of treason. Then a phone call arrives to tell Hochstetter that his orders have advanced to arresting Richter. But of course he finds Richter has disappeared and starts tearing the place apart to find him.
Hogan figures the best way to take the heat off is to fake Richter's death. So they dress a dummy in Richter's uniform and put it in his car, along with a bomb. Newkirk creates a diversion by dressing in German uniform and cutting the wire to fake an escape. Schultz sees what he thinks is Richter in the car, which is now moving off. He shouts that Richter is trying to escape. Hochstetter tries to shoot the tyres, but when the car blows up, he thinks he hit the petrol tank instead.
Hochstetter is on the verge of crying as his orders were to take Richter alive; this could mean the end of his career. Klink is crowing over Hochstetter's misery. But when Hochstetter explains to Himmler over the phone, Himmler is pleased with him, calling it a brilliantly staged accident. Hochstetter is now smiling and says that there will be a good chance he will be decorated and promoted. Now it is Klink's turn to cry. Meanwhile, Richter is taken out of the cooler and is soon on his way to England.