The is a set of four paperback books from the Whodunits series, authored by Hy Conrad and published by Papp Publishers. The books are designed for children ages 8 to 12 and focus on crime solving, mysteries, and sleuths. The titles in the set are "Fallen Gladiator," "Ghostly Note," "Treehouse Spirit," and "Disappearing Neighbor" Each book offers an engaging and interactive experience for young readers who enjoy solving mysteries and unraveling whodunits. The series is sure to captivate and entertain young detectives with its engaging storylines and clever puzzles.