Set during the waning years of World War I, Jean Renoir's The Grand Illusion tells the story of members of the French military, named Captain de Boëldieu (a wealthy man who is a part of the aristocracy) and Lieutenant Maréchal (a working-class man of a lower class than de Boëldieu). Together, the two set out to investigate a blurry spot on a photo that one of their many reconnaissance planes took. The two find a plane and fly to the spot shown in the aforementioned photo to investigate it, but are shot down by a German officer named von Rauffenstein, who takes the two as his prisoner in a prison camp. After the duo is taken back to the aerodrome (the place where aircraft are launched and land after their mission is done), von Rauffenstein sends a subordinate out to talk to de Boëldieu and Maréchal and ask them if they are officers and to invite them to lunch. At lunch, von Rauffenstein and Boëldieu discover that they have something in common with each other: they both come from wealth.
de Boëldieu and Maréchal eat lunch and are then taken to a particularly horrible prisoner-of-war camp. While at the camp, they meet an energetic group of French soldiers who stage a vaudeville-like performance to keep their spirits high and to keep themselves entertained. During the performance, however, Maréchal interrupts so that he could tell everyone that the French army had captured a very important fort from the German army again. The soldiers take the news well and break out in a celebratory song. Because of this song, however, Maréchal is put into solitary confinement, where he suffers tremendously. In the meantime, the soldiers begin to dig escape tunnels but are transferred to another camp before the tunnels can be completed.
de Boëldieu and Maréchal are moved to Wintersborn, a fortress, and prison built inside of mountains that are run by the aforementioned von Rauffenstein, who was injured in battle. von Rauffenstein informs the two men that they should never attempt to escape Wintersborn because the prison was built to be escape-proof. de Boëldieu and Maréchal don't accept von Rauffenstein's proclamation and begin to plot their escape with the help of another man named Rosenthal, whom they had met in a previous camp.
de Boëldieu decides to distract the guards so that Maréchal and Rosenthal could escape. The prisoners cause a commotion, which allows de Boëldieu to position himself somewhere in the fortress. As a result of the commotion, the guards round up the prisoners and do a roll call. As expected, de Boëldieu is missing. But he quickly makes his presence known to the guards, who start to chase him. In turn, Maréchal and Rosenthal grab a rope and escape.
At the same time, the guards start to shoot at de Boëldieu. But von Rauffenstein orders his guards to stop firing at him in the hope that de Boëldieu will turn himself in willingly. de Boëldieu understandably refuses, and von Rauffenstein shoots him in his stomach, condemning him to death. de Boëldieu dies, but not before he and von Rauffenstein have a conversation.
Meanwhile, after de Boëldieu's death, Rosenthal and Maréchal start their journey across the German countryside in hopes of reaching Switzerland, a country that was not involved in World War I. Along the way, Rosenthal injures his foot. He implores Maréchal to leave him and Maréchal does briefly. However, he returns to help Rosenthal. The two then take refuge in a German woman's house named Elsa. Maréchal and Elsa fall in love (despite not speaking each other's languages), but Maréchal feels a sense of duty to go with Rosenthal to Switzerland. He promises, though, that he will return for Elsa and her daughter. Maréchal and Rosenthal leave and eventually safely make their way into Switzerland.
As with all fictional movies, The Grand Illusion was created first and foremost to entertain its audiences. And it certainly was entertaining. In France alone, the film sold over twelve million tickets (it sold many more tickets in countries across Europe and the United States).
With that said, The Grand Illusion is an incredibly complex film. Thematically, the film deals with brotherhood, the conflict between the rich and poor, the aristocracy, and class. The film also discusses themes related to racism, nationalism, war, conflict, World War I, and escape.
Additionally, The Grand Illusion is a fundamentally anti-war film. The film examines how and why fighting a war is usually futile. It also examines just how destructive war is to people in the countries who are fighting the war. That's why Joseph Goebbels and the French government themselves banned the showing of the film during World War II out of fear that it would make the war less palatable for citizens of countries. Because of its anti-war message, governments in the 1930s and 1940s feared the film because of its power.
