It has been labelled a cross between Donna Tartt and Umberto Eco, or F Scott Fitzgerald and Dan Brown, author of The Da Vinci Code.

The Rule of Four, written by two 28-year-old first-time novelists, is fast becoming this year's biggest publishing sensation, with 11 reprints in the US and 325,000 copies sold in the two weeks since it was published.

It was the number one seller on amazon.com last Friday and will reach number three on the New York Times besteller list tomorrow.

Like an amalgam of works by all of the above, The Rule of Four combines Ivy League intrigue, student japes, a mysterious medieval text, sex, architecture and murder.

Describing it as "an extremely erudite thriller" and observing that its authors "are exquisitely educated and very smart", New York Times critic Janet Maslin said: "The real treat is the process of discovery, and those passages are written with precision and bravado."

Reviews have been mixed, but all have agreed the novel taps into a vibrant market for mystery novels involving secret codes. "The combination of history and mystery is very popular right now," Lisa Greig, a Borders marketing manager, told the Washington Post.

The Rule of Four takes as its starting point a real medieval text. The Hypnerotomachia Poliphili, meaning Poliphilo's struggle for love in a dream, was published anonymously in Venice in 1499. Written in Greek, Latin, Hebrew, Arabic, Italian as well as other languages, it is peppered with hieroglyphics and riddles and seems to tell of Poliphilo's dreams of searching for Polia, the woman he loves.

The author's identity is unknown, although there are some hints: an acrostic making use of the first letter of each chapter spells out the words "Brother Francesco Colonna greatly loved Polia." The name could refer to a Dominican monk in Venice at the time or a Roman general.

The Rule of Four introduces Savonarola, the monk who was the scourge of the Medicis in 15th century Florence.

As four present day college students attempt to unravel the book's secrets, they come up against an evil professor, secret societies and dead bodies. The authors, in turn, come up with a new theory about authorship of the Hypnerotomachia.

Ian Caldwell and Dustin Thomason went to school together outside Washington DC. They began work on the novel in 1998 as a way of staying in touch after graduating from Princeton and Harvard respectively. Five years later and after several rejections, their second draft was accepted by the Dial Press. After a further 18 months of rewrites, the book was finished.

Their interest was sparked by a Princeton seminar attended by Caldwell on Renaissance art, science and music.