A first novel, The Rule of Four, by two Ivy League graduates, Ian Caldwell and Dustin Thomason, is off to a very impressive start, landing on PW's fiction chart in the #5 slot after just one week on sale. First printing for the Dial Press book was 85,000 and sales action has been so strong that the book has gone back to press 10 times, for more than 300,000 copies in print. Comparisons to the very popular The Da Vinci Code are natural—here, too, the thriller depends on deciphering codes in an ancient text. In fact, Dial presented the book to buyers by noting the Da Vinci connection. Daniel Blackman, v-p and general manager of B&N.com, said, "That's how we presented it as well, and it's a credible comparison." Blackman and other retailers noted that readers of the Brown oeuvre are looking for something similar; brisk sales of The Rule of Four prove that assessment. Dial's book has the right stuff—codes, an ancient text, intrigue, scholarship, art and unimaginable treachery. The book also has an authenticity via the credentials of its authors. Caldwell, a Princeton grad, presented a paper for a seminar entitled "Renaissance Art, Science and Magic," about a real text, The Hypnerotomachia Poliphill, which included a hidden code. Back in 1998, he and Thomason, friends since they were eight, planned to spend the summer after graduation writing a novel together. Summer turned into an almost six-year project that entailed working and reworking drafts via phone calls and e-mails (during that time, Thomason followed his Harvard graduation with an M.D. and M.B.A. from Columbia). Time well spent, it turns out, and through June 19 the duo will be traveling together to seven Eastern cities promoting the book.