Twenty-five years ago, the ancient Mayans were thought to be a mysterious and peaceful people governed by astronomer-priests. But in 1965, Russian linguist Yuri Knorosov cracked the phonetic code of Mayan hieroglyphic writing in the confinements of his bustling Leningrad study. Today, researchers reveal stories of Mayan blood sacrifices as they uncover a world so foreign as to defy our understanding of it.