Books about books are generally dangerous territory for a writer. Many times they seem to spiral into an overly technical discussion of the author's favorite arcane genre of literature. The writer cannot really help themselves -- they love a book and they want to share their devotion with the world. Occasionally, however, some authors avoid the trap and are able to bring an entertaining and thought provoking story about another book to print. This is the case with THE RULE OF FOUR by Ian Caldwell and Dustin Thomason. In this case we are treated to a narrative that uses a somewhat obscure Renaissance text as another character in the story that is really about friendship, devotion, faith, fanaticism and purpose.

The story focuses on the last semester of four college friends, an unlikely set of listless scholar (Tom), future wall-street yuppie (Gil), working class pre-med (Charlie), and troubled genius (Paul). The other main character in the story is a book, titled the Hypnerotomachia Poliphili, penned sometime near the end of the 15th century in Italy. The book is more than it seems, on the surface it relates a confused and complex story of the visions of a man named Poliphli, but it's really something much more -- something that lies locked, coded in its pages. It's the effort to decode the story that obsessed Tom's father, and left a series of bitter childhood memories. Tom knows more about the Hypnerotomachia through his father's work than all but a handful of scholars, but also knows that he disdains the strange devotion to the book that tainted his childhood and persisted until his father's untimely death.

Tom's attempt to avoid this painful part of his past is undermined by Paul, a brilliant but somewhat troubled fellow student. Paul has also been seduced by the desire to break the code and understand the message that lies hidden in the pages of the Hypnerotomachia. He knows from the first day that they meet that Tom is the son of one of the most noteworthy scholars of the Hypnerotomachia, and assumes that they will seek the hidden answers together. Tom is able to resist Paul's requests for assistance until a series of events triggered by his father's old colleagues renews his interest and he jumps in with both feet. Soon he is seduced, just as his father, and risks losing track of the important things in his life in the quest to solve the riddle.

Just as the Hypnerotomachia has multiple levels locked in its pages, THE RULE OF FOUR is also a multi-layered effort. On the surface it is an engaging story of the quest to solve a puzzle. Beneath that, however, is a deeper story of friendship. It's the fact that the four friends are a diverse group with different interests that provides the lesson here. When one of the friends missteps, the others are there to help him up. While the message of the Hypnerotomachia is carefully locked in codes and ciphers, the message of THE RULE OF FOUR is decoded by the reader as they experience the story.