"Who had told him to call upon her?" Quarles asked.
"In the course of an excited narrative he mentioned two or three names entirely unknown to her, but the man seemed to think that I should have sent her the plans."
"Very curious," Quarles remarked.
"He then became apologetic," Lanning went on, "but all the same left the impression that he did not believe her; in fact, she describes his attitude as rather threatening. It wasn't until after he had gone that she thought she ought to have him followed, and then it was too late. He was out of the street. Probably he had a motor waiting for him. Then she telephoned to me, but I was out, and have only just received her message. What do you make of it?"
"It gives a new turn to the affair," said Quarles reflectively. "It leaves an unpleasant doubt whether Mademoiselle Duplaix is as innocent as she ought to be, doesn't it?"
"I don't think so."
"Would she have telephoned to Lanning if she were guilty?" said Nixon.
"My experience is that where women are concerned it is very difficult to tell what line of action will be followed. Women are distinctly more subtle than men."
Then after a pause the professor went on: "It is difficult to understand how this foreigner could have made such a mistake. You have told us, Mr. Lanning, that there is nothing between you and this lady, but Miss Chilcot had her suspicions, remember, which suggests that, without intending to do so, you have paid her attentions which other people have misunderstood. Now, do you think you have given Mademoiselle Duplaix a wrong impression, made her believe, in short, that you cared for her, and so caused her to be jealous and perhaps inclined to be revengeful?"
"I am sure I have not."