Anna the Adventuress by E. Phillips Oppenheim

Nigel Ennison walked towards his club the most puzzled man in London. There could not, he decided, possibly be two girls so much alike. Besides, she had admitted her identity. And yet -- he thought of the supper party where he had met Annabel Pellissier, the stories about her, his own few minutes' whispered love-making! He was a self-contained young man, but his cheeks grew hot at the thought of the things which it had seemed quite natural to say to her then, but which he knew very well would have been instantly resented by the girl whom he had just left. He went over her features one by one in his mind. They were the same. He could not doubt it. There was the same airy grace of movement, the same deep brown hair and alabaster skin. He found himself thinking up all the psychology which he had ever read. Was this the result of some strange experiment? It was the person of Annabel Pellissier -- the soul of a very different order of being.

He spent the remainder of the afternoon looking for a friend whom he found at last in the billiard room of one of the smaller clubs to which he belonged. After the usual laconic greetings, he drew him on one side.