Librarian Charlie Harris and his cat Diesel are known to everyone who lives in the small town of Athens, Mississippi. Even the rich man James Delacorte, known for his collection of rare books and bad character. James Delacorte turns to Charlie for help - it seems to him that someone living in his mansion is stealing priceless books. But before Charlie had even worked a day in his library, the collector was found dead. Charlie Harris and his famous cat Diesel have to find the killer and avoid becoming his next victims.