Alphonse Tram is unwittingly involved in several murders despite having no memory of committing the crimes. His confusion lead him to confess to his neighbour, Inspector Morvandieu. Alphonse and Morvandieu become the axis around which murders occur.

Gérard Depardieuas Alphonse Tram
Bernard Blieras Inspecteur Morvandieu
Jean Carmetas Le vieil assassin
Michel Serraultas Le comptable
Geneviève Pageas Geneviève Léonard
Jean Benguiguias Le tueur à gages
Marco Perrinas L'homme dérangé en pleine nuit
Carole Bouquetas La jeune fille
Bernard Crombeyas Le médecin
Denise Genceas L'hôtesse au château