In the novel They Came to Baghdad, Catherine Serakis is a young Syrian woman from Damascus. She works at the Olive Branch in Baghdad. When Victoria Jones came to the Olive Branch to look for Edward, she took an instant dislike to Catherine, all the more so when Dr Rathbone the director said that Edward is very well liked by all the girls there, and gets on very well, particularly with Catherine. For Victoria, Catherine was therefore a serious competitor for Edward's affections. Things get even worse when Edward actually discusses Catherine with Victoria, saying "she's awfully nice", "nothing much to look at" but "frightfully sympathetic".
In the later part of the story, Victoria discovers to her cost that Catherine is actually an operative of the secret New Order organisation. In fact she is one of the chief lieutenants working for Edward who is the leader of the gang. Among her duties were several directed against Victoria--she set up and facilitate the kidnapping of Victoria by introducing and bringing her to a hairdresser Miss Ankoumian who used a shampoo session to anaesthetise her. Later Catherine is also Victoria's jailer. Victoria has been disguised to look like Anna Scheele and as the final act, the gang is about to kill her. During this time, Catherine gloats that she is the one the Edward is actually in love with.