Nothing is as it seems at St Rita's, an exclusive girls' boarding school.

The floor has holes from canonballs, the smell in the dining room is disgustingly foul, and the librarian doesn't really exist.

But there is a librarian's assistant, Emily Lime. And she's really a crime-solving genius, who's looking for a new assistant of her own. And booksmart Daphne is just the girl for the job.