“Paris,” said the bird.

“Oh shut your mouth, you stupid bird!” cried Norton in an angry tone, his voice trembling slightly.

“Does the bird’s prattle trouble you?” asked Holmes, making a note in his pocket book, but Norton merely snorted and turned away.

It was then decided that a search of the premises would be made. Norton turned out his pockets at Captain Armstrong’s request, but they contained nothing of interest. The two marines then remained in the drawing room with Norton and his servant, while Armstrong, Holmes and I made a swift search of the house. Twenty minutes later we were obliged to admit defeat, having discovered nothing whatever of a suspicious nature.

“I think it likely he has already passed the papers on,” said Holmes, as we stood upon the upstairs landing, “no doubt to his visitor, the gentleman who passed us in the cab.” For a moment he stroked his chin thoughtfully. “The absence of a safe key is probably the most significant discovery,” he remarked after a moment.

“Why so?” asked Armstrong.

“Norton had no reason to suppose that you suspected him, and thus no reason to dispose of the key. If it were a copy, I think we should have found it here. The fact that we have not rather suggests that it was one of the original set, which was lent to him and has now been taken back, probably by the same man who now has the papers.”

“What are you suggesting?” cried Armstrong incredulously.

“That one of your senior colleagues is a traitor. If the keys are guarded as well as you have described to us, it is the only explanation.”

“I cannot believe it!”

“The papers are worth a lot of money,” remarked Holmes, “and for some men the prospect of wealth is too great a temptation to resist. The parrot’s sqwawkings were curious,” he continued after a moment.

“Do you think they were of any significance?” I asked.

“It is hard to say, Watson. Norton certainly appeared troubled by them. The numbers the bird chanted may be the time of some meeting that has been arranged, or possibly an address somewhere, which it overheard Norton discussing with his confederate. Does your department have any official opinion of Princess Zelda, Captain Armstrong?”

“Indeed,” replied the other. “We know for a fact that she has had dealings with foreign agents for several years, but nothing can ever be proved against her. I will tell you,” he continued, lowering his voice a little, “in the very strictest confidence, you understand, that we have an agent in her household, keeping a close watch upon her. She leaves for the Continent in two days’ time, and the rumour from our men abroad is that she will not be leaving empty-handed. It is said she will be carrying papers of great value, and expects to be paid very handsomely for them.”

“It must be the Army codes,” cried Holmes. “Anything else would be too great a coincidence, under the circumstances. Their plan must be for Norton’s confederate to act as intermediary and pass the papers to the princess before she leaves England. Will your agent in her household be able to see all her visitors over the next twenty-four hours?”

Armstrong nodded. “Certainly. But I doubt that they will risk an open meeting. Although Princess Zelda is not aware that her personal maid is in our employ, she is certainly aware that her movements are closely watched. Tomorrow night, however, the Duchess of Pont gives her annual pre-Christmas party, and Princess Zelda is expected to attend, in the company of the French chargé d’affaires. There might be an opportunity then for the papers to be passed to her.”

“Do you know if any of your senior colleagues will be attending the party?” asked Holmes.

“As a matter of fact,” Armstrong replied, “all three of them are.”

“Then that must be when the papers will be passed. If we could somehow contrive an entrée to the duchess’s party, we might be able to thwart their plans.”

“That might be possible,” said Armstrong abruptly, thumping his fist into his hand. “Yes, by George! I think it can be arranged! The Duchess of Pont,” he explained, “happens to be a second cousin of my mother’s. She is also a great patriot, and I’m sure would appreciate the urgency of the situation. I’ll wire my mother at once and see if she can arrange it!”

“You had best not attend yourself,” said Holmes. “Your presence there might alert them and put them on their guard. Meanwhile, you must leave your men posted here for the next twenty-four hours, to prevent Norton passing any warning to the others, and above all else, you must tell no one of our plan.”

The following day dawned a little clearer, but although a weak sun shone from behind a thin veil of cloud, the air was still cold and the snow remained unmelted in the streets, where the traffic churned it into a brown slush, and heaped it up in great mounds at the kerbside. At eleven o’clock, there was a sharp rap at our door, and Captain Armstrong strode briskly into the room. His manner was as different as could be imagined from that of the previous evening. Gone was the hopeless despair, and in its place was a resolute determination to pursue the matter to a successful conclusion.

“It is all arranged,” said he with a cheerful smile. “You are both invited to attend the duchess’s little soirée this evening. I have also had a message within the last hour from our agent in Princess Zelda’s house. The princess received a note in the post this morning, which our agent managed to read. It was unsigned, and said merely, ‘Be prepared! Someone will approach you this evening using the agreed passwords’.”

“That rather confirms our reading of the situation,” remarked Holmes. “It also suggests that the princess herself does not know the identity of the intermediary. All in all, this evening’s party should be a singularly interesting affair!”

“No doubt,” returned Armstrong. “You must, incidentally, be there by six-forty-five at the latest,” he added, “as the duchess wishes to speak to you privately before the other guests arrive. I shall remain outside the house at the time of the party, with a couple of men. A single whistle will bring us at once.”

“Excellent!” cried Holmes. “I think, Watson,” said he, turning to me gaily with a chuckle, “that you and I had best spend the remainder of the day making certain that our wardrobes are fit for such an exalted occasion!”

At six-forty our cab dropped us in Belgrave Square, and moments later we were conducted up to the Duchess of Pont’s study.

She rose from her desk as we entered and held out her hand. She was a grand and dignified figure, in a handsome gown of dark grey silk, and appeared exactly as I had seen her in photographs in the illustrated papers.

“Captain Armstrong has explained to me the urgent issue that necessitates your presence here this evening,” she began, “and I have instructed my servants to offer you every possible assistance. However,” she continued in a slow, emphatic tone, “there is one thing I must insist upon: there must be no unpleasant ‘incident’. Is that quite clear? Among my guests this evening are the ambassadors of Italy, Russia and the United States, and also Count Wilhelm of Mullenstein, the personal representative of the German Emperor. The editor of the Telegraph will also be here, the deputy editor of The Times, and the chief foreign correspondent of the Berlin Post. The slightest hint of anything untoward would flash round Europe like sheet lightning, and would be an absolute disaster. It is bad enough having that wretched woman in the house, but in that case, I had no choice. She has attached herself recently to the French chargé d’affaires, and I knew he would not come without her. Still, her presence may be of some value if it enables you to bring your problem to a successful conclusion.”

“You need have no anxiety, your Grace,” responded Holmes in a suave tone. “There will be no incident.”