"It was this horrible scandal," said he. "My brother, Sir James, was a man of very sensitive honor, and he could not survive such an affair. It broke his heart. He was always so proud of the efficiency of his department, and this was a crushing blow."

"We had hoped that he might have given us some indications which would have helped us to clear the matter up."

"I assure you that it was all a mystery to him as it is to you and to all of us. He had already put all his knowledge at the disposal of the police. Naturally he had no doubt that Cadogan West was guilty. But all the rest was inconceivable."

"You cannot throw any new light upon the affair?"

"I know nothing myself save what I have read or heard. I have no desire to be discourteous, but you can understand, Mr. Holmes, that we are much disturbed at present, and I must ask you to hasten this interview to an end."

"This is indeed an unexpected development," said my friend when we had regained the cab. "I wonder if the death was natural, or whether the poor old fellow killed himself! If the latter, may it be taken as some sign of self-reproach for duty neglected? We must leave that question to the future. Now we shall turn to the Cadogan Wests."

A small but well-kept house in the outskirts of the town sheltered the bereaved mother. The old lady was too dazed with grief to be of any use to us, but at her side was a white-faced young lady, who introduced herself as Miss Violet Westbury, the fiancee of the dead man, and the last to see him upon that fatal night.

"I cannot explain it, Mr. Holmes," she said. "I have not shut an eye since the tragedy, thinking, thinking, thinking, night and day, what the true meaning of it can be. Arthur was the most single-minded, chivalrous, patriotic man upon earth. He would have cut his right hand off before he would sell a State secret confided to his keeping. It is absurd, impossible, preposterous to anyone who knew him."

"But the facts, Miss Westbury?"

"Yes, yes I admit I cannot explain them."

"Was he in any want of money?"

"No; his needs were very simple and his salary ample. He had saved a few hundreds, and we were to marry at the New Year."

"No signs of any mental excitement? Come, Miss Westbury, be absolutely frank with us."

The quick eye of my companion had noted some change in her manner. She colored and hesitated. "Yes," she said at last, "I had a feeling that there was something on his mind."

"For long?"

"Only for the last week or so. He was thoughtful and worried. Once I pressed him about it. He admitted that there was something, and that it was concerned with his official life. 'It is too serious for me to speak about, even to you,' said he. I could get nothing more."

Holmes looked grave. "Go on, Miss Westbury. Even if it seems to tell against him, go on. We cannot say what it may lead to."

"Indeed, I have nothing more to tell. Once or twice it seemed to me that he was on the point of telling me something. He spoke one evening of the importance of the secret, and I have some recollection that he said that no doubt foreign spies would pay a great deal to have it."

My friend's face grew graver still. "Anything else?"

"He said that we were slack about such matters – that it would be easy for a traitor to get the plans."

"Was it only recently that he made such remarks?"

"Yes, quite recently."

"Now tell us of that last evening."

"We were to go to the theater. The fog was so thick that a cab was useless. We walked, and our way took us close to the office. Suddenly he darted away into the fog."

"Without a word?"

"He gave an exclamation; that was all. I waited but he never returned. Then I walked home. Next morning, after the office opened, they came to inquire. About twelve o'clock we heard the terrible news. Oh, Mr. Holmes, if you could only, only save his honor! It was so much to him."

Holmes shook his head sadly. "Come, Watson," said he, "our ways lie elsewhere. Our next station must be the office from which the papers were taken.

"It was black enough before against this young man, but our inquiries make it blacker," he remarked as the cab lumbered off. "His coming marriage gives a motive for the crime. He naturally wanted money. The idea was in his head, since he spoke about it. He nearly made the girl an accomplice in the treason by telling her his plans. It is all very bad."

"But surely, Holmes, character goes for something? Then, again, why should he leave the girl in the street and dart away to commit a felony?"

"Exactly! There are certainly objections. But it is a formidable case which they have to meet."

Mr. Sidney Johnson, the senior clerk, met us at the office and received us with that respect which my companion's card always commanded. He was a thin, gruff, bespectacled man of middle age, his cheeks haggard, and his hands twitching from the nervous strain to which he had been subjected. "It is bad, Mr. Holmes, very bad! Have you heard of the death of the chief?"

"We have just come from his house."

"The place is disorganized. The chief dead, Cadogan West dead, our papers stolen. And yet, when we closed our door on Monday evening, we were as efficient an office as any in the government service. Good God, it's dreadful to think of! That West, of all men, should have done such a thing!"

"You are sure of his guilt, then?"

"I can see no other way out of it. And yet I would have trusted him as I trust myself."

"At what hour was the office closed on Monday?"

"At five."

"Did you close it?"

"I am always the last man out."

"Where were the plans?"

"In that safe. I put them there myself."

"Is there no watchman to the building?"

"There is, but he has other departments to look after as well. He is an old soldier and a most trustworthy man. He saw nothing that evening. Of course the fog was very thick."

"Suppose that Cadogan West wished to make his way into the building after hours; he would need three keys, would he not, before he could reach the papers?"

"Yes, he would. The key of the outer door, the key of the office, and the key of the safe."

"Only Sir James Walter and you had those keys?"

"I had no keys of the doors – only of the safe."

"Was Sir James a man who was orderly in his habits?"

"Yes, I think he was. I know that so far as those three keys are concerned he kept them on the same ring. I have often seen them there."

"And that ring went with him to London?"

"He said so."

"And your key never left your possession?"

"Never."

"Then West, if he is the culprit, must have had a duplicate. And yet none was found upon his body. One other point: if a clerk in this office desired to sell the plans, would it not be simpler to copy the plans for himself than to take the originals, as was actually done?"

"It would take considerable technical knowledge to copy the plans in an effective way."

"But I suppose either Sir James, or you, or West had that technical knowledge?"

"No doubt we had, but I beg you won't try to drag me into the matter, Mr. Holmes. What is the use of our speculating in this way when the original plans were actually found on West?"