Narcisse is a doorman for a jeweler but dreams of becoming a private detective. The Criminas agency hires him and he comes to the aid of his former boss's nephew, accused of stealing jewelry. He first passes for the accomplice of the young man but soon discovers the culprit.
The farmer Remy has just invented a new fertilizer and spies are trying to seize his documents, taking him for the famous Remy, inventor of a device of interest to national defence.
