What if someone else was living your life?You are sixteen. You live with your father in a big Victorian house on the outskirts of London. Your mother is dead, killed in a train crash two years ago. It is snowing. The snow is falling on the house and the wide yard and the gnarled old tree that everyone calls the Family Tree. It makes you restless. You reach out your hands toward an object you've known all your life, and suddenly the walls melt away. When you open your eyes, you are still in your living room. "Who are you?" asks a girl who looks just like you but is not you. "And what are you doing in my house?" You have stumbled into another version of your life. This girl is sixteen. She lives with your father (her father) in a big Victorian house on the outskirts of London. Your mother (her mother) is not dead. She had a close call in a train crash two years ago. Listen: your mother is calling you (her) now. Michael Lawrence's gripping thriller about a boy and a girl who are the same person but not quite will have you turning the pages late into the night...and talking and thinking and wondering about the shifting nature of identity, time, space, and the cracks that can appear in a train rail, a lifeline, and a family tree.

Four months ago, Alaric and Naia, two teenagers who'd never met, discovered they were living almost identical lives at alternate versions of Withern Rise, their family's riverside home. One day, they accidentally stranded themselves in the wrong realities. It's summer now, and heavy rains have caused the river to overflow. Withern Rise's grounds are under water. When Alaric and Naia find their separate ways into an earlier reality, they meet a boy called Aldous Underwood. Who is he? Could he be the old vagrant Naia has met in the present day? Or is he destined to die tragically young? And will their meeting change Underwood history?

Eight months ago, during the depths of a snowy winter, Alaric and Naia Underwood switched realities. Then in June, as floodwaters surrounded their two versions of the house called Withern Rise, they met again, and tragedy struck. It's autumn now, and Naia is feeling haunted. She's seeing things that shouldn't be there, and an unseen hand draws her into a tangled forest, where she meets an Alaric who lives like a savage. Here, in this dying reality, are the answers to so many questions if she can only reach the man who calls himself Aldous U. Life-changing resolutions are in the air in the worlds of the Underwood See.