Caldwell and Thomason's intriguing intellectual suspense novel stars four brainy roommates at Princeton, two of whom have links to a mysterious 15th-century manuscript, the Hypnerotomachia Poliphili. This rare text (a real book) contains embedded codes revealing the location of a buried Roman treasure. Comparisons to The Da Vinci Code are inevitable, but Caldwell and Thomason's book is the more cerebral-and better written-of the two: think Dan Brown by way of Donna Tartt and Umberto Eco.