At the end of the sixteenth century, the Jesuit Matteo Ricci became the first European allowed into China, arriving with training in geometry and algebra that he quickly realized mattered less to his hosts than his grasp of the calendar. In Chinese imperial thought, mastering the heavens and measuring time correctly underwrote the Emperor's Mandate of Heaven, and Ricci's ability to predict eclipses and refine astronomical instruments became his way into the Forbidden City itself. The film follows three generations of Jesuits over roughly a century as they maneuver for influence at court through astronomy, mathematics, and clockwork, using dramatic recreations alongside access to modern timekeeping laboratories. Science historians and time scientists connect Ricci's sixteenth-century contests over calendars and star charts to today's satellite-driven race for precise time data, arguing that the stakes, who controls the measurement of time, have not really changed. It is a story about science as diplomacy and as leverage, with the Forbidden City's observatories as the stage where East and West first negotiated the point.