It is not a controversial opinion to say that Casablanca is a great movie, full of romance and humor and harrowing drama. Nor is it controversial to say that it’s a wonderfully written screenplay full of quotable lines and interesting characters, the latter of which are diverse and plenty. Everyone rightly remembers the stars of the film (Rick and Ilsa, Captain Renault, etc.) but there are a lot of great minor characters littered throughout Rick’s that make the city seem like a lived-in place.

There’s Rick’s Number 2 man, Carl, a kind-hearted Hungarian who darts around the restaurant keeping things in order and encouraging his boss not to be such a hard man. Buzzing in and out of the cafe is Annina, the young newlywed so hopeful and in love with her husband she seriously considers sleeping with Captain Renault if it means getting a pair of exit visas. Seated at a regular table are the Leuchtags, an adorable Hungarian couple trying to learn English for their move to America and not doing as well as they think. Across town there’s Signor Ferrari, the smarmy and jolly owner of The Blue Parrot looking to purchase the considerable talents of Sam the piano player. Wandering throughout the cafés and streets there’s the charming and nameless Pickpocket, who chivalrously warns others about the dangerous criminal element of Casablanca while helping himself to the contents of their pockets.

Then there’s Yvonne. Played by Madeleine Lebeau, Yvonne only has three scenes in the film, but they’re vitally important because they represent the entire film in miniature. In her first scene, which is just shortly after the introduction of Rick, we learn her backstory: she and Rick shared a one-night stand that meant nothing to him, but everything to her. She tries to reach out to him but is brushed aside, in many ways recalling Rick’s own I’ll-fated romance with Ilsa. Getting tossed aside in the café is like Rick receiving that Dear John letter at the train station. When next we see her it’s much later that same evening and Yvonne has apparently decided to deal with this rejection the same way Rick did: by getting drunk. She makes one final pass at Rick, who rebuffs her and has his Russian bartender take her back to her apartment (“and come right back,” he sternly adds, to the bartender’s dismay).

At this point she disappears from the movie for a long time, surfacing well into Act II for her final scene. When she returns to Rick’s with a German soldier on her arm, marching proudly up to the bar and ordering a long line of expensive alcohol. She’s clearly reveling in the money and power that comes with associating with the Germans, much like Captain Renault, to whom the Nazi atrocities mean very little when they’re so far away. Why should either of them care, as long as the relationship benefits them? Rick lives in this grey area, too. Even though he openly despises the Germans he also doesn’t stand up to them, and doesn’t bat an eye when they drag Peter Lorre’s Ugarte away. Much in the same way Yvonne doesn’t try to stop the fight between her German soldier and the Frenchman at the bar who berates Yvonne for her choice in company. In the world of Casablanca, neutrality is complicity.

All this precedes one of Casablanca‘s most moving moments: the “La Marseillaise” scene, and the final time we see Yvonne on screen. A group of German soldiers start singing the German patriotic song “Die Wacht am Rhein,” which ticks off Victor Laszlo and spurs him to take action. Laszlo approaches Rick’s house band and gets them to play the French national anthem. Everyone in the bar joins in, including Yvonne.

The interesting thing about this sequence is that it’s clearly built around the conclusion to Yvonne’s character arc. There are only three extreme close ups in this sequence, and one belongs to Ilsa, staring lovingly at Laszlo as he leads the band with every ounce of conviction he has for the cause, deepening the conflict of the love triangle. The other two belong to Yvonne.

While everyone else sings the anthem in defiance, reveling in the “fuck you” gesture as they drown out the Germans into submission, it’s very clear that Yvonne is having a much more intimate moment. That close-up reveals tears welling up in her eyes, and you can practically see her remembering the horrors of the occupation of France, the stranglehold the Germans have on her home country. It’s a raw, emotional turning point for the character, one that Rick and Renault will experience later, though neither would ever express it so nakedly. When Renault decides to join the fight against the Nazis he covers up Rick’s murder of Major Strasser and chucks a bottle of Vichy liquor into a waste bin. When Rick makes that same decision he puts the woman he loves on a plane for America, saying goodbye by repeating a significant phrase, though he keeps his eyes dry and his voice steady. Yvonne’s final line before she disappears is an impassioned “Viva la France!” as tears stream down her face, while Rick’s closing line of dialogue is the much more reserved “Louie, I think this is the beginning of a beautiful friendship.” But notice that this declaration is followed by the triumphant return of “La Marseillaise.” It all comes back to that fateful night at Rick’s, when Yvonne rediscovered her pride and foretold the end of the story.