“It is your misfortune, my dear fellow.  No one can blame you.  There is no precaution which you have neglected.  Now, Mr. Holmes, you are in full possession of the facts.  What course do you recommend?”

Holmes shook his head mournfully.

“You think, sir, that unless this document is recovered there will be war?”

“I think it is very probable.”

“Then, sir, prepare for war.”

“That is a hard saying, Mr. Holmes.”

“Consider the facts, sir.  It is inconceivable that it was taken after eleven-thirty at night, since I understand that Mr. Hope and his wife were both in the room from that hour until the loss was found out.  It was taken, then, yesterday evening between seven-thirty and eleven-thirty, probably near the earlier hour, since whoever took it evidently knew that it was there and would naturally secure it as early as possible.  Now, sir, if a document of this importance were taken at that hour, where can it be now?  No one has any reason to retain it.  It has been passed rapidly on to those who need it.  What chance have we now to overtake or even to trace it?  It is beyond our reach.”

The Prime Minister rose from the settee.

“What you say is perfectly logical, Mr. Holmes.  I feel that the matter is indeed out of our hands.”

“Let us presume, for argument’s sake, that the document was taken by the maid or by the valet——­”

“They are both old and tried servants.”

“I understand you to say that your room is on the second floor, that there is no entrance from without, and that from within no one could go up unobserved.  It must, then, be somebody in the house who has taken it.  To whom would the thief take it?  To one of several international spies and secret agents, whose names are tolerably familiar to me.  There are three who may be said to be the heads of their profession.  I will begin my research by going round and finding if each of them is at his post.  If one is missing—­especially if he has disappeared since last night—­we will have some indication as to where the document has gone.”

“Why should he be missing?” asked the European Secretary.  “He would take the letter to an Embassy in London, as likely as not.”

“I fancy not.  These agents work independently, and their relations with the Embassies are often strained.”

The Prime Minister nodded his acquiescence.

“I believe you are right, Mr. Holmes.  He would take so valuable a prize to headquarters with his own hands.  I think that your course of action is an excellent one.  Meanwhile, Hope, we cannot neglect all our other duties on account of this one misfortune.  Should there be any fresh developments during the day we shall communicate with you, and you will no doubt let us know the results of your own inquiries.”

The two statesmen bowed and walked gravely from the room.

When our illustrious visitors had departed Holmes lit his pipe in silence and sat for some time lost in the deepest thought.  I had opened the morning paper and was immersed in a sensational crime which had occurred in London the night before, when my friend gave an exclamation, sprang to his feet, and laid his pipe down upon the mantelpiece.