How quickly she disappears

"It's been twenty years since Elisabeth's twin sister, Jacqueline, disappeared without a trace. Now thirty-year-old Elisabeth is living far from home in a small Alaskan town. She's in a loveless marriage and has a precocious young daughter she loves more than anything but who reminds her too much of her long-missing sister. But then Alfred, a dangerous stranger with a plan of his own, arrives in town and commits an inexplicable act of violence. And he offers a startling revelation: He knows exactly what happened to Elisabeth's sister, but he'll reveal this truth only if she fulfills his three requests. Increasingly isolated from her neighbors and imprisoned by the bitter cold and her own obsession, Elisabeth can almost hear her sister's voice saying, Come and find me. And so she will, even if it means putting herself--and her family--in danger"--