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.