Here's extracts from another couple of good reviews for The Case of the Diamond Shadow..
The first one is from The Reading Stack, http://www.thereadingstack.com/
'The Case of the Diamond Shadow is a wonderfully entertaining detective story with one of the best endings I have read for a long time. Not only is it exciting but the twists and turns will keep young readers guessing all the way!'
The second one is from the YARA site, on which young readers review books: (http://goldcreek.act.edu.au/yara) The review is by 12 year old Ronja, from Canberra:
'I found this book amazing! I couldn't stop reading it until I had finished it end from end! I would recommend it to detective lovers and those who enjoy reading mysteries.'