As I've told you before, I used to read these books to my classes at school. I found that Y4 (8 to 9 year olds) enjoyed Over Sea, Under Stone' as an adventure with just enough threat to make it exciting. The older children remembered my having read OSUS and were keen to try TDIR. Being older (10 to 11 years old), they were able to appreciate the atmosphere and Light v Dark of TDIR. This was not an adventure to be enjoyed but dealt with fear and suspense that a younger audience would have found unpleasant and the stock descriptive 'boring' would have been the result. Anything beyond a particular stage of development in a child was always labelled thus: in other words, 'I don't understand this.'

It's been a long time since I read the others but I'm interested to know what you make of them :)