Under no conceivable circumstances were the plans to be takenfrom the office. If the chief constructor of the Navy desired toconsult them， even he was forced to go to the Woolwich office forthe purpose. And yet here we find them in the pocket of a deadjunior clerk in the heart of London. From an official point of viewit’s simply awful.”
“But you have recovered them？”
“No， Sherlock， no！ That’s the pinch. We have not. Ten paperswere taken from Woolwich. There were seven in the pocketof Cadogan West. The three most essential are gone—stolen，vanished. You must drop everything， Sherlock. Never mind yourusual petty puzzles of the police-court. It’s a vital internationalproblem that you have to solve. Why did Cadogan West take thepapers， where are the missing ones， how did he die， how came hisbody where it was found， how can the evil be set right？ Find ananswer to all these questions， and you will have done good servicefor your country.”
“Why do you not solve it yourself， Mycroft？ You can see as far asI.”
“Possibly， Sherlock. But it is a question of getting details.
Give me your details， and from an armchair I will return you anexcellent expert opinion. But to run here and run there， to crossquestionrailway guards， and lie on my face with a lens to myeye—it is not my metier. No， you are the one man who can clearthe matter up. If you have a fancy to see your name in the nexthonours list—”
My friend smiled and shook his head.
“I play the game for the game’s own sake，” said he. “But theproblem certainly presents some points of interest， and I shall bevery pleased to look into it. Some more facts， please.”
“I have jotted down the more essential ones upon this sheetof paper， together with a few addresses which you will find ofservice. The actual official guardian of the papers is the famousgovernment expert， Sir James Walter， whose decorations andsub-titles fill two lines of a book of reference. He has growngray in the service， is a gentleman， a favoured guest in the mostexalted houses， and， above all， a man whose patriotism is beyondsuspicion. He is one of two who have a key of the safe. I may addthat the papers were undoubtedly in the office during workinghours on Monday， and that Sir James left for London about threeo’clock taking his key with him. He was at the house of AdmiralSinclair at Barclay Square during the whole of the evening whenthis incident occurred.”
“Has the fact been verified？”
“Yes； his brother， Colonel Valentine Walter， has testified to hisdeparture from Woolwich， and Admiral Sinclair to his arrival inLondon； so Sir James is no longer a direct factor in the problem.”
“Who was the other man with a key？”
“The senior clerk and draughtsman， Mr. Sidney Johnson. He isa man of forty， married， with five children. He is a silent， moroseman， but he has， on the whole， an excellent record in the publicservice. He is unpopular with his colleagues， but a hard worker.
According to his own account， corroborated only by the word ofhis wife， he was at home the whole of Monday evening after officehours， and his key has never left the watch-chain upon which ithangs.”
“Tell us about Cadogan West.”
“He has been ten years in the service and has done good work.
He has the reputation of being hot-headed and imperious， but astraight， honest man. We have nothing against him. He was nextSidney Johnson in the office. His duties brought him into daily，personal contact with the plans. No one else had the handling ofthem.”
“Who locked the plans up that night？”
“Mr. Sidney Johnson， the senior clerk.”
“Well， it is surely perfectly clear who took them away. They areactually found upon the person of this junior clerk， Cadogan West.
That seems final， does it not？”
“It does， Sherlock， and yet it leaves so much unexplained. In thefirst place， why did he take them？”
“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 toLondon except to sell them？”
“No， I cannot.”
“Then we must take that as our working hypothesis. YoungWest took the papers. Now this could only be done by having afalse key—”
“Several false keys. He had to open the building and the room.”
“He had， then， several false keys. He took the papers toLondon to sell the secret， intending， no doubt， to have the plansthemselves 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 whenhe was killed and thrown out of the compartment.”
“Aldgate， where the body was found， is considerably past thestation for London Bridge， which would be his route to Woolwich.”
“Many circumstances could be imagined under which he wouldpass London Bridge. There was someone in the carriage， forexample， with whom he was having an absorbing interview. Thisinterview led to a violent scene in which he lost his life. Possiblyhe tried to leave the carriage， fell out on the line， and so met hisend. The other closed the door. There was a thick fog， and nothingcould 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 WestHAD determined to convey these papers to London. He wouldnaturally have made an appointment with the foreign agent andkept his evening clear. Instead of that he took two tickets for thetheatre， escorted his fiancée halfway there， and then suddenlydisappeared.”
“A blind，” said Lestrade， who had sat listening with someimpatience to the conversation.
“A very singular one. That is objection No. 1. Objection No.