With nothing left to live for, a grieving and guilt-ridden Harry Stone enlists to fight on the Western Front. Although withdrawn and solitary, he is befriended by card-sharp Arthur and when the two of them are assigned to drive ambulances, their friendship is sealed. As they sail for France, Harry encounters Rose, a young woman fulfilling her dream of nursing at the Front. With Arthur by his side, amidst the horrors of war, Harry begins to feel purpose to his life once more, but when Rose is placed in danger he must decide if he deserves a second chance at love.