In the novel They Came to Baghdad, Grete Harden is a Danish hospital masseuse travelling to Baghdad.
Members of the secret "New Order" organisation were trying to prevent Anna Scheele from reaching Baghdad. They checked on Grete Harden and discovered that there was no such person--the name and the address she used were fake. They concluded that Grete must be Anna. Accordingly, they kidnapped Grete at Damascus while she was waiting for a connecting flight and sent Victoria Jones to impersonate her. Grete's luggage was searched. Papers Anna was supposed to be carrying were found carefully camouflaged between the leaves of a Danish publication on "Hospital Massage".
Grete was later rescued by British intelligence personnel. It was later revealed that she was actually a British intelligence agent and had been sent as a decoy for Anna. They did not know how Anna Scheele was planning to get to Baghdad but decided to send Grete anyway as a means of keeping the "New Order" organisation distracted.