June 5th, 1944: On the eve of the Normandy landings in Cotentin, Mary, a 12 year old girl, is preparing for his first communion. But the ceremony is interrupted by the Germans, They came to arrest the priest. Desperate, Mary dressed in her beautiful white dress, returns home, where she lives with her parents on the river. That evening, John, a Canadian paratrooper US Army, misplaced by a violent storm arises in the family home to seek help. Lost, he must join as soon as its unity. For this it has to cross the marshes and minefields, with the help of Mary insists that as a guide. During this walk, they will get to know and establish a friendship gradually.