About this book:

In ancient Uruk, the birth of mathematical astronomy emerges through the eyes of Sin-leqi-unninni, a dedicated apprentice scribe. Under the tutelage of his master, Iddin, the young protagonist learns that the heavens are not merely a canvas for divine omens, but a predictable system of cycles that can be measured and calculated. As he masters the "Saros" eclipse cycles and the movements of planets like Jupiter and Saturn, he begins to challenge the traditional authority of the Chief Diviner, Barim-ahi, who relies on subjective interpretations of sheep livers and oil patterns to advise the King.

The narrative expands beyond the ziggurat as Sin-leqi-unninni discovers that celestial patterns correlate deeply with terrestrial life. By integrating astronomical data with the river measurements of the Nilologists and the market-price records of an unlicensed street forecaster named Ur-eshunu, he develops a revolutionary integrated model of the world. This new science is put to the ultimate test when the apprentice must predict a critical frost window, a lunar eclipse, and the spring flood of the Euphrates to secure the city’s grain supply and inform the King's military strategy against the encroaching Assyrians.

The apprentice’s journey is fraught with political peril, including the theft and alteration of his records by a rival, Kashshu-nadin, who is caught between institutional loyalty and personal ambition. Despite this betrayal, Sin-leqi-unninni finds a powerful patron in Queen Uqnitum, who tasks him with managing the royal gardens using his numerical methods. His success in the "Court of Two Lions" proves that the "honest counting" of the days provides a more stable foundation for the kingdom than traditional superstition.

Ultimately, the book celebrates the transition from a world of fear and myth to one of observation and reason. Sin-leqi-unninni's Map of the Heavens becomes a permanent legacy, shifting the power of the future from the whims of gods to the hands of those patient enough to measure the stars. The story concludes with the young astronomer realizing that while the sky is indifferent to humanity, the act of recording its rhythms allows civilization to move in harmony with the vast, interconnected clockwork of the universe.