“When I discovered my loss, Mr. Holmes, which was at eight o’clock this morning, I at once informed the Prime Minister.  It was at his suggestion that we have both come to you.”

“Have you informed the police?”

“No, sir,” said the Prime Minister, with the quick, decisive manner for which he was famous.  “We have not done so, nor is it possible that we should do so.  To inform the police must, in the long run, mean to inform the public.  This is what we particularly desire to avoid.”

“And why, sir?”

“Because the document in question is of such immense importance that its publication might very easily—­I might almost say probably—­lead to European complications of the utmost moment.  It is not too much to say that peace or war may hang upon the issue.  Unless its recovery can be attended with the utmost secrecy, then it may as well not be recovered at all, for all that is aimed at by those who have taken it is that its contents should be generally known.”

“I understand.  Now, Mr. Trelawney Hope, I should be much obliged if you would tell me exactly the circumstances under which this document disappeared.”

“That can be done in a very few words, Mr. Holmes.  The letter—­for it was a letter from a foreign potentate—­was received six days ago.  It was of such importance that I have never left it in my safe, but have taken it across each evening to my house in Whitehall Terrace, and kept it in my bedroom in a locked despatch-box.  It was there last night.  Of that I am certain.  I actually opened the box while I was dressing for dinner and saw the document inside.  This morning it was gone.  The despatch-box had stood beside the glass upon my dressing-table all night.  I am a light sleeper, and so is my wife.  We are both prepared to swear that no one could have entered the room during the night.  And yet I repeat that the paper is gone.”

“What time did you dine?”

“Half-past seven.”

“How long was it before you went to bed?”

“My wife had gone to the theatre.  I waited up for her.  It was half-past eleven before we went to our room.”

“Then for four hours the despatch-box had lain unguarded?”

“No one is ever permitted to enter that room save the house-maid in the morning, and my valet, or my wife’s maid, during the rest of the day.  They are both trusty servants who have been with us for some time.  Besides, neither of them could possibly have known that there was anything more valuable than the ordinary departmental papers in my despatch-box.”

“Who did know of the existence of that letter?”

“No one in the house.”

“Surely your wife knew?”

“No, sir.  I had said nothing to my wife until I missed the paper this morning.”

The Premier nodded approvingly.

“I have long known, sir, how high is your sense of public duty,” said he.  “I am convinced that in the case of a secret of this importance it would rise superior to the most intimate domestic ties.”