Contessina is faced with deciding Maddalena's fate. Cosimo goes to Rome to retake the city and the papacy. Lorenzo finds evidence incriminating Pazzi.

Cosimo is asked to choose a candidate for the vacant seat in the Signoria. Marco is forced to share his suspicions about Lorenzo with Cosimo.

The Medici family returns to Florence, where Albizzi awaits the Signoria's sentence, but the arrival of Pope Eugene IV complicates the situation.

In exile in Venice, Cosimo finds himself drawn to a slave woman. Meanwhile, back in Florence, Contessina runs into her childhood sweetheart.

After Cosimo's arrest, his wife tries to buy a Signoria member's help. Piero seeks to refute the charges, whilst Lorenzo takes a more drastic approach.

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

As the war with Milan takes a heavy toll on Florence, Cosimo boosts morale and the economy by undertaking the impossible: building the cathedral dome.

After 20 years of grooming, Cosimo Medici replaces his late father in Florence's Signoria, where he must decide whether to support a call for war.