The book is set on the Princeton campus during Easter weekend in 1999. The story involves four Princeton seniors, both friends and roommates, getting ready for graduation: Tom, Paul, Charlie and Gil. Tom and Paul are trying to solve the mystery contained within an extremely rare, and mysterious book, the "Hypnerotomachia Poliphili", which was an incunabulum published in 1499 in Venice, Italy; it is a complex allegorical work written in a modified Italian language frequently interspersed with material from other languages as well as its anonymous author's own made-up words.