It tells the story of a dog named Nell who loves to solve mysteries. She accompanies her owner, Peter, to his job as a school caretaker, where she uses her exceptional sense of smell to help find lost items, from a missing football to a stolen teddy bear. But when the school's books start disappearing, Nell takes on her biggest mystery yet. The book explores themes of problem-solving, teamwork, and the joy of reading. Ages:2-6 years