Charles Renoir (Roland Giraud) is in hospital for tests. He thinks that he has a serious illness. He is greeted by a nurse, Janine (Grâce de Capitani), who guides his first steps through the place. Unfortunately for Renoir, there are no more single rooms left. Janine puts him in with a provocative old grouch, René Bertillon (Jean Carmet). From that moment on, Bertillon is obsessed by a single idea: making Renoir's life hell.
The comical and pathetic duel between the two men is refereed by Janine, the bossy and maternal nurse who, moreover, is having an affair with the head doctor.
In the face of the major questions that obsess the two men (life, death, the after life), laughter, wit and derision - embodied by Roland Giraud and Jean Carmet both in their everyday lives and in these roles - are the only fragile but inevitable means of protection. This confrontation and their laughter is a great adventure in this suspended setting of a closed room caught between dreams and reality.