17 year old Julia can't remember anything about her life from more than a year ago, except for falling through an abyss with a mysterious dark-haired boy who cries her name. With her foster mother and sister, she's tried in vain to recover her memories. All she knows is that her falling nightmare terrorizes her night after night, and she always wakes from it at 2:20 a.m.--the same time she appeared on the porch of her current home. Then the Spring Formal dance goes terribly wrong, and Julia learns she's somehow in the wrong time and that her falling nightmare is a glimpse into her real, but still mysterious past. Worse, she's being tracked by a group of immortals called the Timeless, who are determined to send her back into danger to keep the flow of history in order. Julia must avoid the trip at all costs and learn where she's truly from, because if the Timeless catch her, she will die. Things only grow more complicated when attractive but brooding Simon shows up at her school. There's something hauntingly familiar about him--so familiar, in fact, that he may have everything to do with the truth that Julia seeks. Julia finds herself growing closer and closer to him as she works to unravel her true past. But Simon has some secrets of his own, and learning the truth may be her end.