The year is 1997; four entrepreneurs on a Mediterranean cruise propose a challenge to create an object so marvelous, so unique, and so irreplaceable that it would be out of reach for even the richest of the rich. Months later, when Detective Fermín Escartín is invited to a global presentation introducing the Amsterdam Solitaire fountain pen, he has no idea that he is about to become involved in a complicated revenge plot that will lead him from the port of Monte Carlo to Amsterdam, the diamond capital of the world, then to the streets of the old quarter of Zaragoza, his own territory. But this is not a robbery or a murder or anything like Escartín has seen before—he is faced with the seemingly impossible task of solving the perfect crime.