“The effect of our inquiries at Woolwich has in the main beenagainst young Cadogan West； but the indications at the windowwould lend themselves to a more favourable hypothesis. Let ussuppose， for example， that he had been approached by someforeign agent. It might have been done under such pledges aswould have prevented him from speaking of it， and yet would haveaffected his thoughts in the direction indicated by his remarks tohis fiancée. Very good. We will now suppose that as he went tothe theatre with the young lady he suddenly， in the fog， caught aglimpse of this same agent going in the direction of the office. Hewas an impetuous man， quick in his decisions. Everything gaveway to his duty. He followed the man， reached the window， saw theabstraction of the documents， and pursued the thief. In this waywe get over the objection that no one would take originals whenhe could make copies. This outsider had to take originals. So far itholds together.”
“What is the next step？”
“Then we come into difficulties. One would imagine that undersuch circumstances the first act of young Cadogan West wouldbe to seize the villain and raise the alarm. Why did he not do so？
Could it have been an official superior who took the papers？ Thatwould explain West’s conduct. Or could the chief have given Westthe slip in the fog， and West started at once to London to headhim off from his own rooms， presuming that he knew where therooms were？ The call must have been very pressing， since he lefthis girl standing in the fog and made no effort to communicatewith her. Our scent runs cold here， and there is a vast gap betweeneither hypothesis and the laying of West’s body， with seven papersin his pocket， on the roof of a Metropolitan train. My instinctnow is to work from the other end. If Mycroft has given us the listof addresses we may be able to pick our man and follow two tracksinstead of one.”
Surely enough， a note awaited us at Baker Street. A governmentmessenger had brought it post-haste. Holmes glanced at it andthrew it over to me.
There are numerous small fry， but few who would handle so bigan affair. The only men worth considering are Adolph Mayer， of 13Great George Street， Westminster； Louis La Rothiere， of CampdenMansions， Notting Hill； and Hugo Oberstein， 13 Caulfield Gardens，Kensington. The latter was known to be in town on Monday andis now reported as having left. Glad to hear you have seen somelight. The Cabinet awaits your final report with the utmost anxiety.
Urgent representations have arrived from the very highest quarter.
The whole force of the State is at your back if you should need it.
Mycroft.
“I’m afraid，” said Holmes， smiling， “that all the queen’s horsesand all the queen’s men cannot avail in this matter.” He had spreadout his big map of London and leaned eagerly over it. “Well， well，”
said he presently with an exclamation of satisfaction， “things areturning a little in our direction at last. Why， Watson， I do honestlybelieve that we are going to pull it off， after all.” He slapped me onthe shoulder with a sudden burst of hilarity. “I am going out now.
It is only a reconnaissance. I will do nothing serious without mytrusted comrade and biographer at my elbow. Do you stay here，and the odds are that you will see me again in an hour or two. Iftime hangs heavy get foolscap and a pen， and begin your narrativeof how we saved the State.”
I felt some reflection of his elation in my own mind， for I knewwell that he would not depart so far from his usual austerity ofdemeanour unless there was good cause for exultation. All the longNovember evening I waited， filled with impatience for his return. Atlast， shortly after nine o’clock， there arrived a messenger with a note：
Am dining at Goldini’s Restaurant， Gloucester Road， Kensington.
Please come at once and join me there. Bring with you a jemmy， adark lantern， a chisel， and a revolver.
S.H.
It was a nice equipment for a respectable citizen to carrythrough the dim， fog-draped streets. I stowed them all discreetlyaway in my overcoat and drove straight to the address given. Theresat my friend at a little round table near the door of the garishItalian restaurant.
“Have you had something to eat？ Then join me in a coffee andcuracao. Try one of the proprietor’s cigars. They are less poisonousthan one would expect. Have you the tools？”
“They are here， in my overcoat.”
“Excellent. Let me give you a short sketch of what I have done，with some indication of what we are about to do. Now it must beevident to you， Watson， that this young man’s body was PLACEDon the roof of the train. That was clear from the instant that Idetermined the fact that it was from the roof， and not from acarriage， that he had fallen.”
“Could it not have been dropped from a bridge？”
“I should say it was impossible. If you examine the roofs you willfind that they are slightly rounded， and there is no railing roundthem. Therefore， we can say for certain that young Cadogan Westwas placed on it.”
“How could he be placed there？”
“That was the question which we had to answer. There is onlyone possible way. You are aware that the Underground runs clearof tunnels at some points in the West End. I had a vague memorythat as I have travelled by it I have occasionally seen windowsjust above my head. Now， suppose that a train halted under sucha window， would there be any difficulty in laying a body upon theroof？”
“It seems most improbable.”
“We must fall back upon the old axiom that when all othercontingencies fail， whatever remains， however improbable，must be the truth. Here all other contingencies HAVE failed.
When I found that the leading international agent， who had justleft London， lived in a row of houses which abutted upon theUnderground， I was so pleased that you were a little astonished atmy sudden frivolity.”
“Oh， that was it， was it？”