Gennareniello, a crazy inventor, is married to Concettina and lives at home with his son Tommasino, full of tics, his spinster sister and with Matteo, a drawing master who makes plans for his inventions. Driven by his friends, the man courts the young teacher Anna and when his wife notices it, he is forced to run away from home, overwhelmed by the scorn of derision of friends and acquaintances who come to disguise him as a dandy, thus offending his dignity.