Marked is the first novel of the House of Night fantasy series written by P.C. Cast and Kristin Cast.
Young teenagers are selected to enter a four-year period transformation to a vampire and marked with an the unfilled mark of a crescent moon. Those are sent to their local Houses of Night, private schools directed by vampires, specialized in helping the adolescents, called fledglings, survive the Change.
Young fledgling Zoey is unusual: unlike other normal fledglings, she bears a filled mark, a sign that the goddess of vampires, Nyx, has bestowed a great destiny onto her, but she also has to deal with normal high school girl issues:school, boyfriends and the evil popular girl waiting just around the corner.