ISBN-13: 9780147514622 / Angielski / Miękka / 2017 / 96 str.
Humphrey might be the only one who can solve the mystery of the missing treasure hunt prize
Garth has a surprise for his friends when they get to his party--a treasure hunt Riddles are hidden all around his backyard and he put the prize in the best hiding spot of all--Humphrey's cage. Only Humphrey knows something Garth doesn't: someone stole the prize