Dunkirk has become a siege town. While a large number of the army have been evacuated many tens of thousands still remain. Jimmy Langley is injured during fierce fighting trying to hold back the final German advance and taken to a casualty clearing station where Major Newman has been trying to evacuate his wounded patients. However no arrangements have been made for them and they are left behind to face the Germans who arrive on the same day as Churchill makes his famous speech vowing 'we will never surrender'.