Despite being one of the most brilliant mathematicians in the Abbasid caliphate, Alhasan Ibn al-Haytham makes a quiet living in Basra as a scholar and copyist. He's preparing to write a new treatise on vision and light when a strange man wearing unusual clothes kidnaps him and takes him to Cairo, for a meeting with the caliph, Al-Hakim. The “mad king” of the Fatimid caliphate wants Alhasan to utilize his brilliance to dam the mighty Nile River.

What follows is the kind of adventure that the quiet, reserved Alhasan could never have imagined. Alhasan's incredible journey will lead him to the brink of ruin – and perhaps to his most monumental discovery. A novel about one of history's most overlooked scholars, The Prisoner of Al-Hakim is filled with vivid characters, thrilling scenes, and rich philosophical debates. It's a story about how love, faith, and knowledge are ultimately intertwined, and tells us as much about our contemporary times as about bygone eras.