The Double Thirteen

Dr Eustice Hailey took a pinch of snuff, then considered the situation his agitated
young friend, the Honourable Robert Barling, had disclosed to him. While dancing the previous night with his fiancée, Olva Vorloff, a beautiful, tragic-eyed Russian exile, Bob saw her face pale with terror. He had turned just quickly enough to see a man in the doorway, a Russian she had recently passed on the stairs without recognition. The girl had pleaded fatigue and he took her home. The next morning she had vanished.