Onyx reviews: The Rule of Four by Ian Caldwell & Dustin Thomason

The Rule of Four is regularly compared to The Da Vinci Code because the two books feature characters solving complex centuries-old riddles. That's the extent of their similarity, though. The Rule of Four is not a page-turner. Every chapter doesn't end with a cliffhanger and the characters do not traipse across Europe pursued by homicidal members of ancient cabals. It shares more with Donna Tartt's The Secret History and The Name of the Rose than with Code.

This is a good thing.

The title refers to one of the fictional puzzles hidden in the (real) 15^th century Hypnerotomachia Poliphili ("the world's longest book about a man having a dream"), but it also alludes to the ending reign of four friends preparing to graduate from Princeton.

The seniors are as unlike as any four friends could be. The narrator is Tom Sullivan, whose father spent his academic career obsessed with solving the Hypnerotomachia puzzle. His one contribution was a small book recounting the discovery of a letter and a diary that shed light on the manuscript's putative author, Francesco Colonna. Sullivan senior expected his treatise to solidify his academic career; instead, it was derided as literary quackery.

Paul Harris, likewise obsessed with unraveling the Hypnerotomachia, sought Tom out during their freshman year because he recognized his name from the dedication in his father's book. With Tom's reluctant assistance, the duo makes the first real progress in cracking the puzzle in centuries. The enigmatic book issues a siren's call to all who fall within her reach. Tom is sometimes caught up in her spell and, at other times, determined not to repeat his father's life of obsession.

Pulling him in other directions are his girlfriend, Katie, and his future course after graduation. Should he accept a lucrative job with a startup computer company or continue his education? Katie recognizes the Hypnerotomachia's allure, resenting the book's power over Tom. He goes for weeks doing little more than working on its seemingly intractable codes. He barely has time left over for his own studies and his uninspired senior thesis about Frankenstein, let alone for her.

The Rule of Four does have intrigue. A library assistant is murdered after he gives Paul access to a document that has been missing for many years, a diary that was the source of acrimony among a triumvirate of Renaissance scholars—including Tom's father—who once collaborated on their research before becoming bitter rivals. The killing raises the book's stakes because someone is so obsessed by the Hypnerotomachia that he is willing to kill to preserve its secrets for himself.

The Rule of Four is a character-driven tale of friendship, curiosity, drive, ambition and the need young adults have to discover their own identities apart from those of their parents and friends. It's not a perfect book. Some of the campus regulations seem artificially contrived to allow the characters to perform outlandish acts without fear of being caught, and Tom's devotion to Katie doesn't always seem sufficient to explain why he would forego working on the ancient puzzle, especially when Paul is on the verge of solving it. The staging is occasionally confusing, with hours worth of activities packed into what can only be a brief period of time.

Still, this is an enviable and accomplished first work by the duo of writers, a satisfying literary thriller packed with just enough history that readers should come away feeling both educated and entertained.