All 17 year old Julia remembers from more than a year ago is falling through the dark with a mysterious dark-haired boy. With her foster mom and sister, she's tried in vain to recover her memories. Her falling nightmare returns each night, and she always wakes from it at 2:20 a.m.—the same time she appeared on the porch of her foster home. Then the 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, and dangerous, past. Worse, she's being tracked by a group of immortals called the Timeless, who want 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.