“Not at all. They know all they see at Godolphin Street. They know - and shall know - nothing of Whitehall Terrace. Only we know of both events, and can trace the relation between them. There is one obvious point which would, in any case, have turned my suspicions against Lucas. Godolphin Street, Westminster, is only a few minutes’ walk from Whitehall Terrace. The other secret agents whom I have named live in the extreme West End. It was easier, therefore, for Lucas than for the others to establish a connection or receive a message from the European Secretary’s household - a small thing, and yet where events are compressed into a few hours it may prove essential. Halloa! what have we here?”

Mrs. Hudson had appeared with a lady’s card upon her salver. Holmes glanced at it, raised his eyebrows, and handed it over to me.

“Ask Lady Hilda Trelawney Hope if she will be kind enough to step up,” said he.

A moment later our modest apartment, already so distinguished that morning, was further honoured by the entrance of the most lovely woman in London. I had often heard of the beauty of the youngest daughter of the Duke of Belminster, but no description of it, and no contemplation of colourless photographs, had prepared me for the subtle, delicate charm and the beautiful colouring of that exquisite head. And yet as we saw it that autumn morning, it was not its beauty which would be the first thing to impress the observer. The cheek was lovely but it was paled with emotion, the eyes were bright, but it was the brightness of fever, the sensitive mouth was tight and drawn in an effort after self-command. Terror - not beauty - was what sprang first to the eye as our fair visitor stood framed for an instant in the open door.

“Has my husband been here, Mr. Holmes?”

“Yes, madam, he has been here.”

“Mr. Holmes, I implore you not to tell him that I came here.” Holmes bowed coldly, and motioned the lady to a chair.

“Your ladyship places me in a very delicate position. I beg that you will sit down and tell me what you desire, but I fear that I cannot make any unconditional promise.”

She swept across the room and seated herself with her back to the window. It was a queenly presence - tall, graceful, and intensely womanly.

“Mr. Holmes,” she said - and her white-gloved hands clasped and unclasped as she spoke - “I will speak frankly to you in the hopes that it may induce you to speak frankly in return. There is complete confidence between my husband and me on all matters save one. That one is politics. On this his lips are sealed. He tells me nothing. Now, I am aware that there was a most deplorable occurrence in our house last night. I know that a paper has disappeared. But because the matter is political my husband refuses to take me into his complete confidence. Now it is essential - essential, I say - that I should thoroughly understand it. You are the only other person, save only these politicians, who knows the true facts. I beg you then, Mr. Holmes, to tell me exactly what has happened and what it will lead to. Tell me all, Mr. Holmes. Let no regard for your client’s interests keep you silent, for I assure you that his interests, if he would only see it, would be best served by taking me into his complete confidence. What was this paper which was stolen?”

“Madam, what you ask me is really impossible.”

She groaned and sank her face in her hands.

“You must see that this is so, madam. If your husband thinks fit to keep you in the dark over this matter, is it for me, who has only learned the true facts under the pledge of professional secrecy, to tell what he has withheld? It is not fair to ask it. It is him whom you must ask.”