A scientist combines two brains during an operation to create one perfect mind.

Sant'Ilario is a 1923 silent film

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.