La peau de l'ours

Police Chief Ledru, often subject to bouts of nausea takes a series of medical tests and becomes certain that someone is trying to poison him with arsenic. He proceeds by elimination, suspecting each member of his family in turn, in the hopes of discovering the hidden motives of the real assassin. However he accidentally finds out that he has just been the victim of an accident. His relatives forgive him for unfairly suspecting them.