"I presume they were of value?"
"He could have got several thousands for them very easily."
"Can you suggest any possible motive for taking the papers to London except to sell them?"
"No, I cannot."
"Then we must take that as our working hypothesis. Young West took the papers. Now this could only be done by having a false key--"
"Several false keys. He had to open the building and the room."
"He had, then, several false keys. He took the papers to London to sell the secret, intending, no doubt, to have the plans themselves back in the safe next morning before they were missed. While in London on this treasonable mission he met his end."
"How?"
"We will suppose that he was travelling back to Woolwich when he was killed and thrown out of the compartment."
"Aldgate, where the body was found, is considerably past the station London Bridge, which would be his route to Woolwich."
"Many circumstances could be imagined under which he would pass London Bridge. There was someone in the carriage, for example, with whom he was having an absorbing interview. This interview led to a violent scene in which he lost his life. Possibly he tried to leave the carriage, fell out on the line, and so met his end. The other closed the door. There was a thick fog, and nothing could be seen."
"No better explanation can be given with our present knowledge; and yet consider, Sherlock, how much you leave untouched. We will suppose, for argument's sake, that young Cadogan West HAD determined to convey these papers to London. He would naturally have made an appointment with the foreign agent and kept his evening clear. Instead of that he took two tickets for the theatre, escorted his fiancee halfway there, and then suddenly disappeared."
"A blind," said Lestrade, who had sat listening with some impatience to the conversation.
"A very singular one. That is objection No. 1. Objection No. 2: We will suppose that he reaches London and sees the foreign agent. He must bring back the papers before morning or the loss will be discovered. He took away ten. Only seven were in his pocket. What had become of the other three? He certainly would not leave them of his own free will. Then, again, where is the price of his treason? Once would have expected to find a large sum of money in his pocket."
"It seems to me perfectly clear," said Lestrade. "I have no doubt at all as to what occurred. He took the papers to sell them. He saw the agent. They could not agree as to price. He started home again, but the agent went with him. In the train the agent murdered him, took the more essential papers, and threw his body from the carriage. That would account for everything, would it not?"
"Why had he no ticket?"
"The ticket would have shown which station was nearest the agent's house. Therefore he took it from the murdered man's pocket."
"Good, Lestrade, very good," said Holmes. "Your theory holds together. But if this is true, then the case is at an end. On the one hand, the traitor is dead. On the other, the plans of the Bruce-Partington submarine are presumably already on the Continent. What is there for us to do?"
"To act, Sherlock--to act!" cried Mycroft, springing to his feet. "All my instincts are against this explanation. Use your powers! Go to the scene of the crime! See the people concerned! Leave no stone unturned! In all your career you have never had so great a chance of serving your country."
"Well, well!" said Holmes, shrugging his shoulders. "Come, Watson! And you, Lestrade, could you favour us with your company for an hour or two? We will begin our investigation by a visit to Aldgate Station. Good-bye, Mycroft. I shall let you have a report before evening, but I warn you in advance that you have little to expect."
An hour later Holmes, Lestrade and I stood upon the Underground railroad at the point where it emerges from the tunnel immediately before Aldgate Station. A courteous red-faced old gentleman represented the railway company.
"This is where the young man's body lay," said he, indicating a spot about three feet from the metals. "It could not have fallen from above, for these, as you see, are all blank walls. Therefore, it could only have come from a train, and that train, so far as we can trace it, must have passed about midnight on Monday."
"Have the carriages been examined for any sign of violence?"
"There are no such signs, and no ticket has been found."
"No record of a door being found open?"
"None."
"We have had some fresh evidence this morning," said Lestrade. "A passenger who passed Aldgate in an ordinary Metropolitan train about 11:40 on Monday night declares that he heard a heavy thud, as of a body striking the line, just before the train reached the station. There was dense fog, however, and nothing could be seen. He made no report of it at the time. Why, whatever is the matter with Mr. Holmes?"
My friend was standing with an expression of strained intensity upon his face, staring at the railway metals where they curved out of the tunnel. Aldgate is a junction, and there was a network of points. On these his eager, questioning eyes were fixed, and I saw on his keen, alert face that tightening of the lips, that quiver of the nostrils, and concentration of the heavy, tufted brows which I knew so well.
"Points," he muttered; "the points."
"What of it? What do you mean?"
"I suppose there are no great number of points on a system such as this?"
"No; they are very few."
"And a curve, too. Points, and a curve. By Jove! if it were only so."
"What is it, Mr. Holmes? Have you a clue?"
"An idea--an indication, no more. But the case certainly grows in interest. Unique, perfectly unique, and yet why not? I do not see any indications of bleeding on the line."
"There were hardly any."
"But I understand that there was a considerable wound."
"The bone was crushed, but there was no great external injury."
"And yet one would have expected some bleeding. Would it be possible for me to inspect the train which contained the passenger who heard the thud of a fall in the fog?"
"I fear not, Mr. Holmes. The train has been broken up before now, and the carriages redistributed."
"I can assure you, Mr. Holmes," said Lestrade, "that every carriage has been carefully examined. I saw to it myself."
It was one of my friend's most obvious weaknesses that he was impatient with less alert intelligences than his own.
"Very likely," said he, turning away. "As it happens, it was not the carriages which I desired to examine. Watson, we have done all we can here. We need not trouble you any further, Mr. Lestrade. I think our investigations must now carry us to Woolwich."
At London Bridge, Holmes wrote a telegram to his brother, which he handed to me before dispatching it. It ran thus:
See some light in the darkness, but it may possibly flicker out. Meanwhile, please send by messenger, to await return at Baker Street, a complete list of all foreign spies or international agents known to be in England, with full address.
Sherlock.