Publisher's Synopsis
What is the secret of the old castle on the hill, and why are the locals so afraid of it?
When flashing lights are seen in a distant tower, Philip, Dinah, Lucy-Ann and Jack decide to investigate - and discover a very sinister plot concealed within its hidden rooms and gloomy underground passages.
Other titles in the Adventure series:
The Island of Adventure
The Valley of Adventure
The Sea of Adventure
The Mountain of Adventure
The Ship of Adventure
The Circus of Adventure
The River of Adventure
