It is the end of May 1940, the British government has put out a call for fishing boats to help rescue the British soldiers trapped at Dunkerque and Aiden is the son of a fisherman with access to his father's dory--his parents forbid him to go, but Aiden has already lost one brother to the war, and his other brother is somewhere over there with the British Expeditionary Force; so despite his fear of the ocean, he and his best friend Sally set out to rescue George and his fellow soldiers.