The explorer Smith leaves with Laura, a beautiful but naive girl, in search of Professor Berti, who mysteriously disappeared in Africa in the midst of one of his researches.
Toto (Aldo Fabrizi), a Roman coachman with an old fashioned horse-drawn carriage who objects to the competition from motorised taxis, doesn't want his daughter Nannarella to go out with Roberto, a young taxi driver. But it is Roberto who helps him when he gets into trouble with a former client, Mary Dunchetti (Anna Magnani), an arrogant singer.
Armando Conforti, his family and his friends have a business: they sell souvenirs near St. Peter's, in Rome, they change dollars, in short they get along.
