Academy of Secrets The Angel Chronicles (Book One)

On the night of her eighteenth birthday, Anastasia Starr learns a horrible secret about her life. Anastasia isn't who she thought she was. After a strange man informs her about her family's deep dark secret, her mother goes missing. Desperately searching for clues as to where her mother could be and who Anastasia really is, Anastasia stumbles upon a letter from her older brother who died nine years ago. With the help of her younger sister Felicity, and her life long best friend Oliver Van Dyck, the three pack their bags and head across the continent to their only lead on Anastasia and Felicity's mother. Their clues lead them straight to a strange academy in New York where the trio soon enroll in. Let's just say, grades aren't the only things the trio should be worrying about.