Rule of Four

At the center of The Rule of Four are four Princeton roommates approaching graduation and an ancient text called the Hypnerotomachia Poliphili. It's a 15th-century book written in several languages, and is full of secrets, puzzles, and clues that are supposed to lead to a treasure buried in a vault in Rome. One of the roommates, Paul, is doing his senior thesis on the book and believes he's stumbled across a clue that might solve the mysteries within the book.