The Gozerian Codex is a mysterious ancient book that holds many secrets of the "Gozerians", who revered it as even somewhat their own holy bible, and it is needed to obtain in order to summon their god, Gozer, into our world. It was hidden in New York City Public Library and discovered by a member of the cult, Edmund Hoover, who murdered a woman named Eleanor Twitty in order to get to it.