The book is a sprawling narrative that intertwines two timelines: the first during World War II, focusing on the efforts of cryptographers and mathematicians working to break Axis codes, and the second in the late 20th century, following a group of entrepreneurs and hackers establishing a data haven in Southeast Asia. The novel explores themes of cryptography, mathematics, and the history of computing, weaving together real historical figures with fictional characters. As the plot unfolds across different continents and eras, it delves into the impact of information technology on society and the perpetual conflict between governments and individuals over the control of information and privacy.

A Harvard symbologist awakens in a Florentine hospital with no memory and finds himself thrust into a frantic international chase after a reclusive scientist obsessed with Dante, following a trail of art, architecture and cryptic puzzles drawn from the Divine Comedy; aided by a young physician, he races through Florence, Venice and Istanbul to decipher clues and stop a plot to release a bioengineered agent intended to address catastrophic population growth, all while confronting fraught ethical questions about sacrifice, security and the value of human life.