Plot

While Albizzi uses the plague to turn Florentines against Cosimo and his dome, two Medici family members are lost. Marco forces a shocking confession.

Florence suffering from the Black Plague, Cosimo barely manages in time to move his family -like most rich- to their safer ancestral vineyard estate outside the city, but the epidemic still kills his mother, who finally reconciles with him over the absurd blame for his twin's childhood death and her and Giovanni's heartless manipulations. Albizzi turns the people against Cosimo and even the workers against his dome by blaming the plague on God's wrath at the Medici's usury. Cosimo returns to Florence and turns the cathedral into a hospice for plague victims to save the dome. Lorenzo overrules Contessina and sells the family's wool business making their financial problems public. Albizzi has Cosimo arrested after Marco breaks into a house to gather evidence on Giovanni's murder. Twenty years earlier, Cosimo and Contessina struggle to trust each other and make their marriage work. .—KGF Vissers

The Medici take refuge in the country to avoid contagion, but Marco stays in Florence to investigate the Corona, a family that seems to have something to do with Giovannis murder. Shortly after breaking into their palazzo and finding the couple both dead of the plague, Marco hears that some men are dismantling the dome piece by piece. Albizzi has managed to foment the citizenry against Cosimo and his project, accusing him of the crime of usury. When Cosimo learns of the situation, he decides to return to Florence, even though his mother PICCARDA has come down with the plague. Cosimo succeeds in saving the dome, which is still under construction, by turning the cathedral into an emergency hospital. However, in the meantime, in addition to Piccarda, the baby Lucrezia was carrying also dies. Albizzi then invents a ploy to get Cosimo arrested and held for trial.