The Kneebone Boy

Otto, Lucia, and Max Hardscrabble don't live a normal life. Their mom has been missing for years, and for all they know she could be dead. Their dad leaves for weeks at a time for work; he paints portraits of former royalty who are no longer so royal. He is about to leave again, but this time it is different. They usually have time to prepare, but they just got home from school, and their bags are packed. They also find out that they're not staying with Mrs. Carnival (thank goodness, because Max is tired of popping the boil on the back of her neck) but instead are going to stay with their dad's cousin, Angela, in London. The only problem is, when they get to Angela's, they find only a mean neighbor, Angela's mean dog, and a mean dogsitter at her house. I won't tell the whole story, but just know that the kids meet a tattooed man, they come upon a very oddly shaped castle and its folly (you'll have to read the book to find out what a castle's folly is), and they end up acquiring a 5-legged cat. You'll also just have to read this book by Ellen Potter to find out why it is called The Kneebone Boy. I would recommend if for about 4th grade and up.