It's been a year since Alice Booker disappeared — a year since she went to work one morning at the Byron County Library and never came back. Her son, Max, is still trying to come to terms with her disappearance when he strikes up a unusual friendship with Becky Smart, a tough new kid at Lincoln Middle School that everyone quickly learns not to mess with. When Max discovers there's been a fire in his mom's old office at the library, he and Becky form the Book-Smart Detective Agency to investigate. What they discover about the fire, and about the strange circumstances surrounding it, plunge them into a mystery that is almost too impossible to be imagined.