[1] The film is based on the 1957 novel That Awful Mess on Via Merulana by Carlo Emilio Gadda.

A neighbour, Liliana Banducci, employs a servant girl, Assuntina.

Her fiancé, Diomede, tries to escape when he sees police tailing Assuntina.

Liliana's cousin, Dr. Valdarena, pays her a visit, only to find her corpse on the floor.

But before calling police, Valdarena removes an envelope addressed to him from the sideboard.