‘‘I’m still not sure of the importance of the Codex,’’ said Billy.‘‘Beyond its intrinsic value as a historical document, the Cortéz Codex was proof of Cortéz’s treason. He was hiding a vast treasure from King Charles. In those days the monarchy received a quinto, one-fifth of any plunder from any expedition to the New World. By that time Cortéz himself was so powerful that the only way to deal with him was by having him excommunicated by the Inquisition, in which case all his lands and treasures would be forfeit to the Church, which would in turn pass on an agreed-upon proportion to the crown. It was exactly the kind of thing the Nazis did to the Jews in the thirties and Roosevelt did to the interned Japanese after Pearl Harbor. Government -sanctioned theft, all neat and tidy and done according to the laws of the day.’’‘‘Follow the money,’’ murmured Finn.‘‘Generally a wise course to follow as a historian, ’’ said Jumaire. He sipped his coffee, then lit another of his foul-smelling cigarettes.‘‘Why would anyone be interested in the Codex now?’’ Finn asked.‘‘Because it is a treasure map, of course,’’ answered the bookseller.