This started pretty well with a dinner party where you quickly learn that the perfect marriage is not as great as it looks. The twist is revealed pretty early so there wasn't any motivation to keep reading. I was annoyed with how Grace seemed to have little common sense, I was annoyed by the language Millie used because it seemed like a stereotype of a person with Down's syndrome, and I was turned off by how unrealistic it seemed. Maybe I just wasn't in the right mood. If you're looking for a better psychological thriller, check out "Dark Matter" or "The Good Goodbye." I read both recently, and those were page turners that kept me reading and guessing.