This was released the same year as Fires Were Started which is often listed among the great British films. Both are tributes to the bravery of the London fire services during the blitz. Humphrey Jennings' picture is a fake documentary which scripts actual firemen. Whereas this is an Ealing comedy-drama shot in a realistic style with actors.
It was Basil Dearden's first release as solo director and will never make any best-ever lists. There's obviously a pitiful budget and the script is particularly poor. Tommy Trinder's jokes are terrible, he can't act and his gobby-Cockney persona is a matter of personal taste. James Mason is mostly on the periphery of the action in an insubstantial role.
The rest of the cast are Ealing stalwarts who are more at home with the background tomfoolery. Which is mostly about Tommy's greyhound. William Hartnell stands out in a more dignified cameo as a survivor of the Spanish Civil War. All the situations are familiar, whether dramatic or comic.... plus the standard mustn't grumble stoicism.
Yet even despite itself, a palpable hum of realism gets into the circuit. Partly because of how skilfully Dearden cuts in newsreel footage from the blitz. And that impression common to many films made in the war years, that this horror is actually going on, somewhere. And because of the authentic heroism the story reflects.