Milly, 17, has had problems with the girl she sees everywhere, Amelia, who seems to be almost a part of her. This has been occuring ever since her parents were killed in a car crash. When her grandpa and she move into her Aunt Rachel's house, the mysterious Milly seems to quickly become more and more dangerous. Meanwhile, she also falls instantly in love with Blake. Near the end, there are some major plot twists and some interesting things uncovered by her family.
