Publisher's Synopsis
Mrs Mannering thinks that a peaceful holiday in the Welsh mountains couldn't possibly land the children in another dangerous adventure.
How wrong she is! Philip, Dinah, Lucy-Ann and Jack are soon up to their necks in the mystery of a rumbling mountain, roaming wolves, and a mad genius who plans to rule the world.
Other titles in the Adventure series:
The Island of Adventure
The Castle of Adventure
The Valley of Adventure
The Sea of Adventure
The Ship of Adventure
The Circus of Adventure
The River of Adventure
