Mr. Goon, the policeman, is determined to solve the new mystery of Peterswood on his own until Freddy, Pip, Harry, Daisy, and Betty discover his secret. It seems that a gang of jewel thieves has its headquarters in their town! Soon the five friends will once again become the Famous Five and, together with Buster, their dog, will take on the task of uncovering the thieves and finding the precious necklace they snatched in their last heist. Will they succeed?