Insurance man Bernard Blier (Charles) invites young tax inspector Michel Auclair (Maurice) home for dinner as a kind gesture after seeing him at his office. It is Tuesday. The diagnosis for Auclair's health is not good and Blier refuses him an insurance policy. However, Blier likes Auclair and feels sorry for him. At dinner, the ungrateful Auclair meets with Blier's wife Madeleine Robinson (Fernande). We fast forward in time from this initial meeting and Auclair and Robinson are now lovers and they set about a plan to kill Blier so they can romance one another without the stamp-collecting Blier lurking around all the time.
The film keeps you watching as you wonder how things are going to pan out. I didn't expect what happens. The cast are ok in their parts although Auclair is thoroughly horrible and slightly unconvincing as a poetic tax inspector. I wonder how different it all would have been if Auclair had come to dinner on Wednesday instead of Tuesday?