Written by William Le Queux
Copyright 1903
3rd adventure in the collection Secrets of the Foreign Office. British Princess 'Edna' (not her real name) of England has disappeared while attending a ball in the German capital. She was wearing a necklace from the Crown Jewels and three of its stones were recently offered for sale in Amsterdam. Duckworth Drew is sent to locate the missing royalty who was either kidnapped or on a romantic escapade.
Here are the pages I have of it.