Now, in ordinary circumstances I should have refused that invitation point-blank, but when I reflected that I was bound to make certain inquiries of Mrs Blain, I, with apparent reluctance, accepted.

“Mother will be most delighted to see you. We have tennis very often, and boating always. It’s awfully jolly. Come down the day after to-morrow—in the afternoon. I shall tell mother that I met you in the street and asked you down. She must, of course, never know that I came here to see you,” and she laughed at her little breach of the convenances.

“Of course not. I won’t give you away,” I said. Then suddenly recollecting, I added: “May I get you a cup of tea?”

“Oh, no, thanks, really,” she answered. “I’ve been in Regent Street to do some shopping, and I had tea there. I was on my way home, but thought that, being alone, I’d venture to try and find you.”

“I’m very glad we have met,” I said enthusiastically, for, truth to tell, I saw in her opportune invitation a means by which I might get at the truth I sought. There was something extremely puzzling in this allegation that the calm-mannered, affable Mrs Blain, whom I had known so well, was the actual tenant of the mysterious house in Phillimore Place. Then, looking at her steadily, I added: “In future our relations shall be, as you suggest, those of friendship, and not of affection—if you really wish.”

“Of course,” she replied. “It is the only sensible solution of the situation. We are both perfectly free, and there is no reason whatever why we should not remain friends—is there?”

“None at all,” I said. “Tell your mother that I shall be most delighted to pay you a visit. You have a boat, I suppose?”

“Oh, yes. And a punt, too. This season I’ve learned to punt quite well.”

I smiled.

“Because that pastime shows off the feminine figure to greatest advantage,” I observed. “Girls who punt generally wear pretty brown shoes, and their dresses just a trifle short, so that as they skip from end to end of the punt they are enabled to display a discreet soupçon of lingerie and open-work stocking—eh?”