On an expedition to the famous wreck of 'Titanic', 16-year-old Marley Faulkner discovers a mysterious journal, and feels as if she's finally found someone who understands her. Full of the tragic tales of a forgotten soul, the book's ending leaves Marley mourning for a girl she's never even met. Or has she? The journal seems to be written for Marley, describing emotions she's certain nobody else in the world could feel but her. Could there be something that the girl in the journal, written nearly a century ago, is trying to tell her? And why does every possible explanation lead back to a single golden locket? Soon, Marley finds that through the locket--and the help of some new, unexpected friends--reaching the past and the girl from the journal isn't as impossible as she thought.

She's a time-traveler now, in a strange place where things are not always what they seem, and in a time where hundreds of lives are on the line. And she's the only one who knows enough to save them all. But how can Marley save anyone from the past when she can't even remember there's a present? How can she be a hero when the love of her life may be the very one who's making her forget? And that's not all--she may only have four days left to live.