Holmes gave a whistle of surprise.
"You can write me down an ass this time, Watson," said he. "This was not the bird that I was looking for."
"Who is he?" asked Mycroft eagerly.
"The younger brother of the late Sir James Walter, the head of the Submarine Department. Yes, yes; I see the fall of the cards. He is coming to. I think that you had best leave his examination to me."
We had carried the prostrate body to the sofa. Now our prisoner sat up, looked round him with a horror-stricken face, and passed his hand over his forehead, like one who cannot believe his own senses.
"What is this?" he asked. "I came here to visit Mr. Oberstein."
"Everything is known, Colonel Walter," said Holmes. "How an English gentleman could behave in such a manner is beyond my comprehension. But your whole correspondence and relations with Oberstein are within our knowledge. So also are the circumstances connected with the death of young Cadogan West. Let me advise you to gain at least the small credit for repentance and confession, since there are still some details which we can only learn from your lips."
The man groaned and sank his face in his hands. We waited, but he was silent.
"I can assure you," said Holmes, "that every essential is already known. We know that you were pressed for money; that you took an impress of the keys which your brother held; and that you entered into a correspondence with Oberstein, who answered your letters through the advertisement columns of the Daily Telegraph. We are aware that you went down to the office in the fog on Monday night, but that you were seen and followed by young Cadogan West, who had probably some previous reason to suspect you. He saw your theft, but could not give the alarm, as it was just possible that you were taking the papers to your brother in London. Leaving all his private concerns, like the good citizen that he was, he followed you closely in the fog and kept at your heels until you reached this very house. There he intervened, and then it was, Colonel Walter, that to treason you added the more terrible crime of murder."
"I did not! I did not! Before God I swear that I did not!" cried our wretched prisoner.
"Tell us, then, how Cadogan West met his end before you laid him upon the roof of a railway carriage."
"I will. I swear to you that I will. I did the rest. I confess it. It was just as you say. A Stock Exchange debt had to be paid. I needed the money badly. Oberstein offered me five thousand. It was to save myself from ruin. But as to murder, I am as innocent as you."
"What happened, then?"
"He had his suspicions before, and he followed me as you describe. I never knew it until I was at the very door. It was thick fog, and one could not see three yards. I had given two taps and Oberstein had come to the door. The young man rushed up and demanded to know what we were about to do with the papers. Oberstein had a short life-preserver. He always carried it with him. As West forced his way after us into the house Oberstein struck him on the head. The blow was a fatal one. He was dead within five minutes. There he lay in the hall, and we were at our wit's end what to do. Then Oberstein had this idea about the trains which halted under his back window. But first he examined the papers which I had brought. He said that three of them were essential, and that he must keep them. 'You cannot keep them,' said I. 'There will be a dreadful row at Woolwich if they are not returned.' 'I must keep them,' said he, 'for they are so technical that it is impossible in the time to make copies.' 'Then they must all go back together to-night,' said I. He thought for a little, and then he cried out that he had it. 'Three I will keep,' said he. 'The others we will stuff into the pocket of this young man. When he is found the whole business will assuredly be put to his account.' I could see no other way out of it, so we did as he suggested. We waited half an hour at the window before a train stopped. It was so thick that nothing could be seen, and we had no difficulty in lowering West's body on to the train. That was the end of the matter so far as I was concerned."
"And your brother?"
"He said nothing, but he had caught me once with his keys, and I think that he suspected. I read in his eyes that he suspected. As you know, he never held up his head again."
There was silence in the room. It was broken by Mycroft Holmes.
"Can you not make reparation? It would ease your conscience, and possibly your punishment."
"What reparation can I make?"
"Where is Oberstein with the papers?"
"I do not know."
"Did he give you no address?"
"He said that letters to the Hotel du Louvre, Paris, would eventually reach him."
"Then reparation is still within your power," said Sherlock Holmes.
"I will do anything I can. I owe this fellow no particular good-will. He has been my ruin and my downfall."
"Here are paper and pen. Sit at this desk and write to my dictation. Direct the envelope to the address given. That is right. Now the letter:
"Dear Sir:
"With regard to our transaction, you will no doubt have observed by now that one essential detail is missing. I have a tracing which will make it complete. This has involved me in extra trouble, however, and I must ask you for a further advance of five hundred pounds. I will not trust it to the post, nor will I take anything but gold or notes. I would come to you abroad, but it would excite remark if I left the country at present. Therefore I shall expect to meet you in the smoking-room of the Charing Cross Hotel at noon on Saturday. Remember that only English notes, or gold, will be taken.
"That will do very well. I shall be very much surprised if it does not fetch our man."
And it did! It is a matter of history--that secret history of a nation which is often so much more intimate and interesting than its public chronicles--that Oberstein, eager to complete the coup of his lifetime, came to the lure and was safely engulfed for fifteen years in a British prison. In his trunk were found the invaluable Bruce-Partington plans, which he had put up for auction in all the naval centres of Europe.
Colonel Walter died in prison towards the end of the second year of his sentence. As to Holmes, he returned refreshed to his monograph upon the Polyphonic Motets of Lassus, which has since been printed for private circulation, and is said by experts to be the last word upon the subject. Some weeks afterwards I learned incidentally that my friend spent a day at Windsor, whence he returned with a remarkably fine emerald tie-pin. When I asked him if he had bought it, he answered that it was a present from a certain gracious lady in whose interests he had once been fortunate enough to carry out a small commission. He said no more; but I fancy that I could guess at that lady's august name, and I have little doubt that the emerald pin will forever recall to my friend's memory the adventure of the Bruce-Partington plans.
The Adventure of the Cardboard Box
By