This is the story of how an East End of London A.F.S. unit made good. It starts just before the war when a nice couple, Bob and Nan, want to get married. The war blasts their hopes and Bob signs on with the A.F.S., who are having a recruiting drive. The regular firemen - under MacFarlane the station officer, and Ted Robins, a leading fireman - despise the A.F.S. Indeed Bob's pals are a scratchy lot. They include Tommy, a kennelman, and Sam, a petty dockside thief. MacFarlane and Ted set out to break the heart of the A.F.S. boys and give them discipline. The boys fight back. The humors and events of this process cover the period up to the blitz. Subsidiary stories are a feud between Tommy and Ted over Susie, an A.F.S. girl; Tommy's dog which he runs at the races without success; Sam's petty thieving and feud with the local 'bobby' who is out to lay him by the heels; and Bob and Nan's efforts to marry and get a home together. Then in the big blitz of September, 1940, all acquit themselves like heroes and comrades. Bob has to watch his dearly won little home go up in flames while he plays water in the opposite direction on a warehouse: meanwhile Nan has a baby in the middle of a raid. Tommy the kennelman, dies in a fruitless attempt to save his enemy MacFarlane, and even Sam fishes his special 'bobby' out of a dock basin on the end of a boat hook. The film ends with the christening of Bob's baby. It is named "Tommy" after the heroic little kennelman. This film was a tribute to the men of the National Fire Service for their unforgettable devotion to duty during the Air Raids of 1940... They are ready now as then to answer the call whenever the bells go down.