This is an attention-grabbing adventure from start to finish, that will likely appeal most to the older end of the 9-12 age range. The book is long and the plot may be complex for a younger reader. But kids will enjoy the unique talents of each member of the Society, and will be challenged by the mind-bending tests throughout. Each of the four main characters is alone in the world -- one is an orphan, one has been abandoned by a parent -- but this strengthens the bond between them, and their familial situations are all resolved in the end.