Enid Blyton The Mystery of the Missing Man: Book 13
 
A brilliant mystery series from bestselling author Enid Blyton, perfect for fans of The Secret Seven. 

The Trottevilles have a house guest named Eunice, and Fatty will do anything to avoid her. While hiding from Eunice his disguise leads a mystery right to him: there's an escaped prisoner in Peterswood who is also a master of disguise. Now Fatty, Larry, Daisy, Pip and Bets have to find the man and avoid Eunice at the same time...