Pope Alexander VI justifies his imprisonment of Caterina by accusing her of trying to kill him in November 1499 with letters impregnated with poison, as a response to the Papal bull which had deprived the Countess of her fiefdoms.

Even today it is not known if the accusation was founded or not.

Machiavelli believed that Caterina had tried to poison the Pope while other historians, such as Jacob Burckhardt and Ferdinand Gregorovius, are not certain.

An inconclusive and unfinished trial had taken place, and Caterina remains imprisoned until June 30, 1501, when she is released by Yves d'Allègre, who has come to Rome with the army of Louis XII for the conquest of the Kingdom of Naples.

Alexander VI alleges that Caterina had signed documents renouncing all of her fiefs, because in the meantime his son Cesare, with the acquisition of Pesaro, Rimini and Faenza, had been appointed Duke of Romagna.

After a brief stay in the residence of Cardinal Riario, Caterina embarks from Livorno to Florence, where her children are waiting for her.