When no one can find where Junior monkey went, Huckle, Lowly and Sally are saddled with his baby sister while they try to solve the Missing Monkey Mystery. They track down the clues but only after they realize the baby sister?s constant ?moobie moobie? meant movie movie do they realize Junior Monkey went to the movies to see the new pirate movie. Pig Will and Pig Won't invite their friends to become members of their secret club. When Huckle and the others go searching for the secret clubhouse, they discover the Pig Twins trapped in a tree house because their rope ladder fell down.