In the midst of World War II, Canadian pilot Max Vatan is on an undercover mission in North Africa. There, he encounters Marianne Beauséjour, a fearless agent of the French Resistance, and together they undertake a risky plan to eliminate a high-ranking Nazi officer. What begins as a fleeting romance transforms into a passionate love affair as they survive the mission. They decide to marry and start a new life together in London, where the horrors of war seem a bit more distant.