The second exciting installment in Enid Blyton's Adventure series
Why is everyone so afraid of the castle on the hill, and what dark
secrets lurk inside its walls? Philip, Dinah, Lucy-Ann, Jack, and Kiki
the parrot are on holiday in the countryside, staying on the side of
Castle Hill. When flashing lights are seen in a distant tower, they
decide to investigate--and discover a very sinister plot concealed
within its hidden rooms and gloomy underground passages.