After years in foster care, April gets to live in a mansion where she and four other children are caught up in a mystery related to a missing heir, a lost legacy, and the Phantom.

"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."--