Ottavio is a quarrelsome old man of seventy who lives in the Testaccio neighbourhood of Rome in a flat that looks like a junk shop but appearances are misleading in that he is rich, having made a fortune from lending money. He also owns the entire building where he lives and rents out an apartment to a former lover from his younger days, Velia, a retired actress who keeps him company and another to two sisters, Adua and Vittoria, who cook for him. In order the guarantee himself a minimum of security, Ottavio has also rented a flat to a young police inspector and another to the son of his lawyer and thus avoid paying his lawyer’s bills. Ottavio has also gone blind and this certainly does nothing to improve his nasty character.
Ottavio has a collection of very valuable artwork by 16th century artist, Maarten Van Heemskerck that he keeps in an ancient safe at home and occasionally takes out and touches for the pleasure this gives him.
Everyone of the film’s characters attention is focused on these drawings, Alessandro Cortesi, Ottavio’s lawyer’s son, was the first to discover them and together with Mario, a penniless coffee shop owner up to his ears in debt, he formulates a plan to replace the drawings with copies.
Adua, Vittoria and Velia would all love to get rid of Ottavio and after discovering the value of the artwork, they decide to try and get their hands on them as well.
Ottavio would likewise love to rid himself of the three old women and asks Inspector Natali to find his (Ottavio’s) one living relative, his niece Clara, daughter of his sister, Emilia. Natali finds her and brings the girl to Rome and her arrival ruins everyone’s plans to steal Ottavio’s artwork. Clara has never met her uncle because he was estranged from her mother and the rest of the family following a mysterious quarrel. Alessandro, Mario and the three old women all want to get Clara on their side, but once the girl finds out their criminal intention, she is shocked and upset. She has also realised the extent of her uncle’s awful character and one evening she goes to visit Mario at his bar and gets drunk.
The inhabitants of Ottavio’s building as well as Mario all decide it is time to get their hands on his pictures. The morning after Ottavio is found dead and the safe is empty. The police are called in and the young and ambitious Inspector Natali asks to take part in the investigation lead by Dr Vanzetta who is convinced that Mario and Clara killed Ottavio. Natali thinks the reality is much more complex. Everything points to Dr Vanzetta’s being right and Natali begins a race against time to discover the murderer. He succeeds with lots of help from a much older police officer called Caruso and the case is closed.
One evening, Caruso is putting his papers in order when he discovers proof of the fact that the murder of Ottavio and the theft of his artwork is, in reality, the result of a complex and intricate plot.