Troy Spiers is indeed seriously weird. Obsessed with, and brilliant at, numbers, he is also erratic, undisciplined, sometimes swears and is violent. It is quite possible he has an autistic spectrum disorder, but autism is not specifically mentioned. His dad thinks he is barmy, his mum thinks he's just being a boy ('boys are different'), but his older sisters, Ness and Claire, are fully aware that something is seriously wrong. Claire, who tells the story, is the middle child, the one who always ends up helping sort out Troy's messes. And she resents this. She has a secret second person inside herself whom she calls Clarry, who says all the awful things about Troy that she can't say aloud. The things Troy gets up to are truly horrendous and often comic in their awful way, and when dad finally leaves (temporarily) to sort himself out, even mum has to admit that Troy needs help - as do they all. There is hope at the end that they will get it and that Troy's maths genius will be recognised. A good story about a child both lovable and impossible and the effect this has on his family, the neighbours and school.