Possibly because of the doubt now existing in his mind, this time he felt less certain of its authenticity. After some study he thought that some further samples of the genuine handwriting might be helpful, and walking down to Oxley’s office, he asked if the solicitor could oblige him with them. Oxley handed him four letters, and when French had critically examined these he found his suspicions strengthened. While by no means positive, he was now inclined to believe Whymper’s was a forgery. He therefore sent the lot to the Yard, asking for an expert opinion to be wired him.

In the meantime he decided he would concentrate on a point which he felt would be even more conclusive than forged letters: the matter of Mrs. Palmer-Gore’s invitation to Ruth. If Roper had got rid of Ruth so that the coast might be clear for the robbery, he had provided the invitation. He had either written it himself or he had arranged the circumstances which caused Mrs. Palmer-Gore to do so. If he had done either of these things he was pretty certain to be guilty.

The only way to learn the truth was to interview Mrs. Palmer-Gore. French therefore took the evening train to York, and nine o’clock found him at Oakdean, Ashton Drive, asking if the lady of the house could see him.

Mrs. Palmer-Gore was a big, rather untidy, kindly-looking woman of about fifty. French, rapidly sizing her up, introduced himself in his real character, apologised for his late call and begged her kind offices. If she wouldn’t mind his not giving her the reason of his inquiry for the moment, he should like to ask a question. Would she tell him just why she had asked Miss Ruth Averill to York some eight weeks previously?

Mrs. Palmer-Gore was naturally surprised at the inquiry, but when she understood that the matter was serious she answered readily.

“Why, I could scarcely have done anything else. Mr. Averill’s note was phrased in a way which would have made it difficult to refuse.”

“Mr. Averill’s note? I didn’t know he had written.”

“Yes, he wrote to say that he hoped he was not presuming on an old friendship in asking me whether I would invite Ruth to spend a day or two. He explained that she had recently been rather run down and depressed, and that the one thing she wanted—a day or two of cheerful society—was just the thing he couldn’t give her. If I would condone a liberty and take pity on her he did not think I would regret my action. He went on to say Ruth was greatly interested in roses, and as he was sure I was going to the flower show, he wondered if I would add to my kindness by allowing her to accompany me. He said that Ruth was longing to see it, but that he had no way of arranging for her to go.”

“I’m quite interested to hear that,” French returned. “It rather falls in with a theory I have formed. Had you often had Miss Ruth to stay with you?”

“Never before. In fact I had only seen her three or four times. Some twelve years ago I spent a day at Starvel and she was there. Besides that I met her with Mr. Averill a couple of times in Leeds.”