The Mostly True Story of Jack by Kelly Barnhill (2011) Little Brown Books

A juvenile urban fantasy novel about a boy whose parents are getting divorced and while his brother gets to spend the in-between time until their parents get their new places to live, he has to go stay with an Aunt and Uncle he barely knows.  His mother and father forget him too easily.  He’s not in any family pictures, his mother doesn’t even always remember who he is when she’s talking to him.

As he leaves, his brother surprises him with a gift of his old skateboard, which Jack hides, because he doesn’t want his mother to say he can’t take it with him.

At his eccentric Aunt and Uncle’s home, he finds almost all walls are covered with books.  He makes a friend, a first for him, a girl whose twin brother was taken when he was younger and who came back with horrible scars on one side of his face.  She’s the terror of the bully who is the son of the richest and most powerful man in town – Mr. Avery.

But Mr. Avery wants Jack dead so he can control the magic that lives under the town.