Five years ago, Nora Wilder disappeared. The older of her two daughters, Zadie, should have seen it coming, because she can literally see things coming. But not even her psychic abilities were able to prevent their mother from vanishing one morning. Zadie's estranged younger sister, Finn, can't see into the future, but she has an uncannily good memory, so good that she remembers not only her own memories, but the echoes of memories other people have left behind. On the afternoon of her graduation party, Finn is seized by an echo more powerful than anything she's experienced before: a woman singing a song she recognizes, a song about a bird... When Finn wakes up alone in an aviary with no idea of how she got there, she realizes who the memory belongs to: Nora. Now, it's up to Finn to convince her sister that not only is their mom still out there, but that she wants to be found. Against Zadie's better judgement, she and Finn hit the highway, using Finn's echoes to retrace Nora's footsteps and uncover the answer to the question that has been haunting them for years: Why did she leave? But the more time Finn spends in their mother's past, the harder it is for her to return to the present, to return to herself. As Zadie feels her sister start to slip away, she will have to decide what lengths she is willing to go to to find their mother, knowing that if she chooses wrong, she could lose them both for good.