Book 4 in the award-winning Elfhome series. Even though they attend a school of gifted students in New York City, child geniuses Louise Mayer and her twin sister Jillian have always felt alone in the world, isolated by their brilliance. Shortly before their ninth birthday, they make an amazing discovery. They're not alone. Their real mother was astronaut Esme Shenske and their father was the famous inventor, Leonardo Dufae. They...