... since it could refer to both or either main characters Olivia Harwood (Ann Todd) and Mark Bellis (Ray Milland). The two outwardly seem as different as possible. They meet on a ship voyage from Jamaica to Britain when Olivia nurses Mark through a bout of malaria. She is penniless other than for a small property she owns in London and has been recently widowed. Her late husband, a missionary, died of malaria himself after the two had served in Jamaica for several years. Mark is a con man on the run, and out of funds he reluctantly has headed back to London - where he is also wanted by the law - to find those funds and get out of British controlled territory altogether.
At first Mark sees Olivia as just another mark for his cons and uses her attraction to him as a means of control. His actual girlfriend is a rather talkative floozy - Kitty - that he can only take in small doses. He does seem to prefer the quiet demeanor of Olivia, at least when he's got his thinking - or should I say plotting - cap on. However, Olivia begins to really enjoy the art of the con as taught to her by Mark and becomes an apt and inventive pupil. Their joint mark - an old school girl friend of Olivia's, the foolishly trusting Susan, played by Geraldine Fitzgerald, who is married to an adviser to the Queen. Olivia seems somewhat bitter that her life has turned out so impoverished when she was the brightest girl at school while the dim-witted Susan has the world at her feet through the accident of marriage. She uses this perceived inequitable outcome as justification for her actions.
Mark's feelings then become somewhat confused. He begins to have actual feelings for Olivia as he begins to realize that she is as cunning and lethal as he - she just needed a push to get her to have the courage of her lack of convictions.
This one has many interesting twists and turns, however do remember that this is a British production and is therefore probably going to seem somewhat understated for American fans of 40's noir. If you can understand that I think you'll like this one a great deal. I know I did.