A few months after the Pazzi Conspiracy, Lorenzo is still animated by the spirit of revenge. There is a distant clash between Lorenzo and Pope Sixtus IV; the cruel count Riario - the last of the conspirators left alive - tries to take advantage of this conflict. A Dominican friar arrives in Florence who seems capable of reading Lorenzo's heart: Girolamo Savonarola.

The entry into the field of the Kingdom of Naples alongside the papal troops is likely to mark the end of Florence. Among the Priors there are those who doubt Lorenzo, but the Magnificent, determined not to let Florence fall into the hands of his enemies, finds a stratagem to deprive the Priors of authority. Lorenzo decides to leave for Naples to try to break the encirclement and restore peace.

Arriving in Naples with Bernardi, Lorenzo finds it difficult to convince King Ferrante of Aragon to abandon the alliance with the Pope. While the Magnificent tries to win the king's trust, Florence remains under siege: the people and Clarice herself fear that Lorenzo has abandoned them.

Seven years have passed and Lorenzo hopes to close the accounts with the Pope by obtaining the signing of a peace treaty between the various Italian rulers. Riario hopes to induce Lorenzo to return to open war. While the Magnificent faces this new diplomatic crisis, his mother Lucrezia involves Clarice in the management of the bank. Worn out by the constant clash with Sixtus IV, Lorenzo decides to start his son Giovanni on an ecclesiastical career hoping to increase the influence of the Medici in the Roman Curia. The Treaty of Bagnolo, signed by all the Italian rulers, marks the triumph of the Medici family and Lorenzo, who has become the deciding vote of Italian politics.