October 1502. As Cesare Borgia sets out to invade the Florentine Republic, Niccolò Machiavelli is sent to spy on him and to glean details of his nefarious plan. But when Borgia asks Machiavelli to write his life story, their bond gains complexity and nuance: ultimately, they both aspire to everlasting fame and to achieve it, they need each other, for the one's sword can only rule in eternity via the pen of the other.