The film is an ensemble piece that covers the period between 27 August 1939 and 9 September 1940, when World War II began and London was subjected to aerial bombing, and is a tribute to the solidarity of not just those engaged in service, but among the British people as a whole.

[1] It was produced by Michael Balcon and directed by Basil Dearden and was intended to give praise to the British Auxiliary Fire Service (AFS).

Although the plot employs fictitious landmarks and localities, many of the incidental shots were taken at actual fires caused by the air raids on London in the previous two years.

[1] The film was released at nearly the same time as the similar Fires Were Started, a fictional "documentary" that used actual firemen instead of professional actors, and as a result was sometimes reviewed unfavorably by comparison.

Tommy Turk (Trinder) is a light-hearted gambler who avoids work, living with his mother (Varley) who runs a local fish and chip shop.

Tommy and Bob meet in The Hopvine, a pub run by Ma and Pa Robbins (Muriel George and Pierce), whose son Ted (Mason) is a fireman with the London Fire Brigade.

Sam, a small-time thief of barrels of Guinness, inadvertently joins the service while trying to avoid the clutches of Eastchapel Police Constable O'Brien (Richard George), who dogs him with the persistence of Javert.

Tommy discovers Short Head has been losing because Ma Turk has been feeding her doughnuts, and he enters her in a high-stakes race on 7 September, planning to wager all his money.

Some time after the fire is out, all the survivors and their families gather in the bombed local church to christen the baby, who Nan and Bob have decided to name "Tommy".