In a moment of madness a middle-aged, married and respectable pharmacist kills a young woman who is sun-bathing by a lake. Unable to take in what he has done, he flees from the scene of the crime and behaves as if nothing has happened. Eventually her boyfriend is charged with the crime and, in a strange twist of fate, the killer finds himself serving on the jury.
as Grégoire Duval, pharmacien
as Le docteur Hess, vétérinaire
as Le procureur général
as Geneviève Duval, l'épouse de Grégoire
as Sylvain Sautral, l'ami de la victime, photographe et accusé
as Me Andreux, l'avocat de la défense
as Le médecin légiste
as Le pêcheur sur sa barque
as Alice Moreux, témoin à l'audience et maîtresse de Sylvain
as Mme Sevestrain, témoin à l'audience
as Catherine Nortier, la victime
as Le président du tribunal
as Le percepteur
as La fille de Grégoire et Geneviève
as Henri Souchon, le patron de la brasserie
as Mme Souchon, la patronne de la brasserie
as Le juge d'instruction
as Albert Testut, un témoin à l'audience
as Le commissaire de police
as Laurent Duval (René Renal), le fils de Grégoire et Geneviève
as Philibert, l'employé de la pharmacie
as La danseuse du cabaret