El Enigma del Cuatro = The Rule of Four

Blurb

The Rule of Four is a novel written by the American authors Ian Caldwell and Dustin Thomason, and published in 2004. Caldwell, a Princeton University graduate, and Thomason, a Harvard College graduate, are childhood friends who wrote the book after their graduations.
The Rule of Four reached the top of the New York Times Bestseller list, where it remained for more than six months.