Word of the find spread slowly. Among Elias’s customers was a retired professor of linguistics, Dr. Ana Ruiz, who claimed the marginalia contained shorthand from a Cold War correspondence course—chess as clandestine pedagogy, opening lines used to encode phrases. Another patron, a young tournament player named Marco, took the book home and began to work through a neglected Sveshnikov line. He found an idea in the annotations—a timely pawn sacrifice—and used it to win the local club championship a month later. He scribbled “Thanks, Marta?” in the margin and slipped the book back on the shelf.