This film – far from conventional as a part of Marcel Carné's canon – could easily be dismissed (or relished) as a Hollywood-style screwball thirties comedy, maybe especially because it's set in an Anglophone country and because Jacques Prévert's script is based on J. Storer Clouston's novel His First Offence (1912). There's more to it than that though. Certainly there are some preposterous things happening: Inspecteur Bray (Pierre Alcover) thinking all the milk bottles are an antidote to poison; the fact that no one (including Margaret Molyneux (Françoise Rosay)) should be thought to have been murdered in the first place; that the milkman Billy (Jean-Pierre Aumont) should be arrested for the supposed murder; that a 'sleeper' should be employed by the police to discover things in his dreams; that an employee in a Chinese hotel, told to get a bunch of flowers, should mug men with flowers in order to get them; and on and on.
It's hopeless to relate the events in the film as they just don't add up, but then if we look at the themes of this we can't help but see a kind of sense: the world is riddled with corruption and absurdity, there's very little truth to be found anywhere, and anyway how can anyone be trusted to make sense of anything anyway? Everything's scewed, and pretence abounds: Irwin Molyneux (Michel Simon) is the detective novelist Félix Chapel; Margaret is also Daisy (to William Kramps (Jean-Louis Barrault)); and the greedy, hypocritical, self-seeking bishop Soper (Louis Jouvet) disguises himself as a Scotsman to re-find the compromising comment on a Folies Bergère programme by another Daisy (a dancer of 'loose' morals) that he's left at Molyneux's home. An anarchist criticism of religion, the law, the family, all institutions?
Certainly this is a satire on British behaviour: the necessity to keep up appearances, the hiding of everything (including the sexual organs Scotsmen are said to hide under their kilts); the London fog; etc. But there's more to this than is beneath a sporran.