The Rule of Four

The Rule of Four follows Princeton seniors Tom Sullivan and Paul Harris on the eve of their 1999 graduation, as they close in on solving the Hypnerotomachia Poliphili — a genuine, five-hundred-year-old Renaissance text, coded across seven languages, that has defeated scholars since its 1499 publication. Tom's late father was consumed by the book for decades; Paul has staked his academic future on finishing what he started.

A long-lost diary surfaces with the key to the manuscript's final cipher, and within hours a fellow student of the text is murdered. What follows is a tightening cycle of revelations and deaths that pulls both young men deeper into the book's five-hundred-year-old mystery even as their own friendship, and their last days of college, run out.

Co-written by Ian Caldwell and Dustin Thomason, the novel blends an erudite, puzzle-box thriller with a bittersweet coming-of-age story about the end of college and the start of adulthood.