The story takes place during World War II, when Allied counterintelligence agent Max (Brad Pitt) and French spy undercover Marianne (Marion Cotillard) meet in Casamblanca, a strategic military location. In order to fulfill their common vision of assassinating the German ambassador, they have to pretend to be a couple. At the beginning, there were repeated misunderstandings and conflicts between Max and Marianne, who had very different personalities, but as time went on, when they experienced some critical moments of life and death and helped each other, the fake play between the two slowly became real, and they fell in love. In the end, the mission was successfully completed, the lovers finally got married, they got married, and had the fruit of love. Max, who thought that life would go on like this for a long time, began to suspect that his wife's true identity was a Nazi spy by chance.