Winterborne Home for Mayhem and Mystery — Ally Carter

Five orphans. Two sword-wielding vigilantes. One mansion. No rules.

April thought she had her happy ending. After all, she has her new house and new friends and new guardian. But she also has a very big new secret.

The kids of Winterborne House are the only ones who know that Gabriel Winterborne -- famous billionaire and terrible cook -- is really a sword-wielding vigilante.

What they don't know is that he's not the only one.

When a masked figure breaks in, looking for something -- or someone -- it's clear that Gabriel has met his match, and now no one is safe. April and her friends will have to solve a decades-old mystery in order to hang on to the most important thing in the world: each other.