Excerpt from Emma in the Night by Wendy Walker, plus links to reviews, author biography & more

That was the year of my parents' divorce. That was the year I told them what I knew—that I could see what was going to happen. I told them that Emma and I should not live with our mother and her new boyfriend, Mr. Martin, and his only child—a son named Hunter.

My parents' divorce was not a surprise to me. Emma said she wasn't surprised either, but I didn't believe her. She cried too much for that to be true. Everyone thought Emma was tough, that nothing bothered her. People were always wrong about Emma because she could react to upsetting things with an unsettling hardness. She had dark hair, like our mother, and her skin was very soft and pale. When she was a teenager, she discovered bright red lip gloss and dark black eye shadow, and how she could hide behind them like paint covering a wall. She would wear short skirts and tight sweaters, mostly black turtlenecks. I don't have just one word to describe how I saw her. She was beautiful, severe, tortured, vulnerable, desperate, ruthless. And I admired her and envied her and drank in every moment she would give any piece of herself to me.

Most of the pieces were small. Many of them were meant to hurt me or exclude me or win points with our mother. But sometimes, when our mother was asleep and the house was quiet, Emma would come to my room and crawl into my bed. She would get under the covers and lie very close to me, and, sometimes, she would wrap her arms around me and press her cheek into my shoulder. It was then that she would tell me things that fed me and kept me warm and made me feel safe even when I woke up to our mother's winter mood. Someday it will just be the two of us, Cass. You and me and no one else. I can remember her smell, the warmth of her breath, the strength of her arms. We'll go wherever we want and we'll never let her in. We won't even care anymore. I can still hear her voice, my sister whispering to me in the night. I love you, Cass. When she said these things to me, I thought nothing could ever touch us.

I let Emma convince me to betray our mother during the divorce. She could see the next move of every player on the board. She could change their course by changing her own. She was responsive, adaptable. And she was never committed to any particular outcome except her own self-preservation.

Cass, we need to live with Daddy. Don't you see? He will be so sad without us. Mom has Mr. Martin. Dad only has us. Do you understand? We have to do something and do it now! Or it will be too late!

Emma didn't have to tell me this. I understood all of it. Our mother's boyfriend, Mr. Martin, moved into our father's house the second our father moved out. His son, Hunter, went to boarding school, but he lived with us when he came home for vacations and weekends, and he came home a lot. Mr. Martin's ex-wife had moved to California a long time before we ever knew them. Mr. Martin was "semiretired," which meant he'd made a lot of money and now played a lot of golf.

I could see that our mother never loved our father, Owen Tanner. She ignored him so glaringly and with such indifference that it became difficult just to look at him, to look at the pain that radiated from his body. So, yes, our father was sad.

I told Emma that I could see our father's sadness. What I didn't tell Emma was that I could see other things as well. I could see the way Mr. Martin's son looked at Emma when he came home from school, and the way Mr. Martin looked at his son looking at Emma, and the way our mother looked at Mr. Martin when he was looking at them. And I could see that this was going to result in a bad future.

But seeing the future is a worthless gift if you don't have the power to change it.

And so when the woman from the court asked me, I said I wanted to live with my father. I said that I thought things would be bad in our house with Mr. Martin and his son. I think Emma was surprised by my courage, or perhaps taken aback at what she perceived to be her influence over me. In any case, when I made this move on the board, she adjusted her course and sided with our mother, sealing forever her position as the most favored child. I never saw it coming. Everyone believed her and no one believed me because I was only eleven and Emma was thirteen. And because Emma was Emma and I was me.

Excerpted from Emma in the Night by Wendy Walker. Copyright © 2017 by Wendy Walker. Excerpted by permission of St. Martin's Press. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.