Ian Caldwell and Dustin Thomason
Princeton. Good Friday, 1999. On the eve of graduation, two students are a hairsbreadth from solving the mysteries of the Hypnerotomachia Poliphili. Famous for its hypnotic power over those who study it, the five-hundred-year-old Hypnerotomachia may finally reveal its secrets -- to Tom Sullivan, whose father was obsessed with the book, and Paul Harris, whose future depends on it. As the deadline looms, research has stalled -- until an ancient diary surfaces. What Tom and Paul discover inside shocks even them: proof that the location of a hidden crypt has been ciphered within the pages of the obscure Renaissance text.

Armed with this final clue, the two friends delve into the bizarre world of the Hypnerotomachia -- a world of forgotten erudition, strange sexual appetites, and terrible violence. But just as they begin to realize the magnitude of their discovery, Princeton's snowy campus is rocked: a longtime student of the book is murdered, shot dead in the hushed halls of the history department.

A tale of timeless intrigue, dazzling scholarship, and great imaginative power, The Rule of Four is the story of a young man divided between the future's promise and the past's allure, guided only by friendship and love.

SPOILER: sent in by E.C.B. who says... The book is well written and has a very cool story. Unfortunately bad timing puts in the shadows of the Da Vinci Code. Rest assured that the book is too thought-out to be a copy or cash-in on the Da Vinci Code-wave.

Two students at the university of Princeton are researching a Renaissance text which goes by the name of Hypnerotomachia Poliphili.

The Hypnerotomachia Poliphili text has astounded researchers for years because of its many (not so apparent) layers. The story told by the text is not in fact the message which is conveyed by its writer.

The two students in the novel are Paul and the story's narrator Tom. Tom has been haunted by the Poliphili since his father was a premier expert on it. He seems to be unable to escape the text and all it's drama.

Paul on the other hand has devoted his life to the secret of the Poliphili and he willingly spends every waking minute researching the text.

Also playing roles of some importance are the professors who are also or have been working on the text (and are in turn haunted by it, important later).

True to audiences needs Paul and Tom make minor breakthroughs which turn into bigger breakthroughs. Envious fellow (senior) researchers show their true colours and an unhealthy kind of commitment and zeal. Paul slowly turns into a hermit on campus with Tom as his only lifeline, but he discovers that the book is actually an intricate puzzle. Solving the first puzzle grants the reader access to the next, raising the bar with every puzzle. Until ultimately the secret is revealed.

The reader, through passing the puzzles as a test of love for art and culture, is granted access to a great treasure. Priceless works of art, poetry and renaissance science saved by the writer of the Hypnerotomachia Poliphili from destruction by the hand of Savonarola, a crusading priest who turned against the debauchery of the De Medici family of Florence (another 'true fact' Da Vinci style).

Savonarola led a (short-lived) uprising against the power of the De Medici family which was highlighted by the burning of books and paintings. The Hypnerotomachia Poliphili reveals where the saved works of art and poetry are hidden.

The finale of the book revolves around a building on fire in which Paul (having figured out the secret) is trapped and presumably killed. But of course Tom is later clued into the fact that Paul did escape and ultimately found the treasure and most likely indescribable wealth