* The Mystery: The Five go on holiday to a remote moor in Yorkshire where they meet a strange man named Mr. Harris who seems to be hiding something. They discover a mysterious cave and a strange object inside it.
* The Search for Clues: The Five are determined to uncover the secret of Mystery Moor. They find clues suggesting there might be hidden treasure and encounter a group of suspicious characters.
* Danger and Adventure: As the Five investigate further, they find themselves in danger. They face a treacherous storm, encounter smugglers, and are threatened by a menacing dog.
* The Truth Revealed: Through their courage and ingenuity, the Five solve the mystery of Mystery Moor. They find the hidden treasure, but it turns out to be much more than just gold and jewels.
* A Happy Ending: The Five have another exciting adventure and learn the importance of friendship and teamwork. They also demonstrate their courage and resilience in the face of danger.
It's important to note that while this is the last book in the series, it is not the final adventure of the Five. Enid Blyton wrote many other stories featuring the Famous Five, so there are more adventures to be had!