Max Vatan (Brad Pitt) and Marianne Beauséjour (Marion Cotillard) are World War II operatives who never reveal their true identities. After falling in love during a risky mission, they hope to leave all that double-dealing behind them and start new lives. Instead, suspicion and danger envelop their marriage as both husband and wife become pitted against each other in an escalating, potentially lethal test that has global consequences.