Alaric Underwood is a 16-year-old boy who lost his mother, Alex Underwood, two years prior in a train crash. While snowed in at home with only his zany aunt for company, he reflects on memories of his mother. He looks at a model of his house carved from an old oak tree inside a glass dome--something his mother made, which she called a folly. The folly takes Alaric to a parallel universe, where his mother is still alive. However, in the other life, his mother had a girl instead of a boy. Alaraic comes face-to-face with his female counterpart, Naia.
In Naia's world, Alex was in the train that crashed, but she had a 50/50 chance of survival, and managed to survive in that lifetime. Naia and Alaric meet, and try to make sense of what happened. Naia discovers she can travel to Alaric's world just as he did to hers. Alaric is happy for the first time in two years when entering Naia's world, because his mother is alive there. Alex meets Alaric in the cemetery and is naturally curious about the stranger with a resemblance to her daughter. Later, Naia and Alaric try to enter each other's parallel universe simultaneously, and discover that it cannot be done.
The review of this Book prepared by Cassie