He sat opposite to me, and lit a cigarette in his old, nonchalant manner.  He was dressed in the seedy frockcoat of the book merchant, but the rest of that individual lay in a pile of white hair and old books upon the table.  Holmes looked even thinner and keener than of old, but there was a dead-white tinge in his aquiline face which told me that his life recently had not been a healthy one.

“I am glad to stretch myself, Watson,” said he.  “It is no joke when a tall man has to take a foot off his stature for several hours on end.  Now, my dear fellow, in the matter of these explanations, we have, if I may ask for your cooperation, a hard and dangerous night’s work in front of us.  Perhaps it would be better if I gave you an account of the whole situation when that work is finished.”

“I am full of curiosity.  I should much prefer to hear now.”

“You’ll come with me to-night?”

“When you like and where you like.”

“This is, indeed, like the old days.  We shall have time for a mouthful of dinner before we need go.  Well, then, about that chasm.  I had no serious difficulty in getting out of it, for the very simple reason that I never was in it.”

“You never were in it?”

“No, Watson, I never was in it.  My note to you was absolutely genuine.  I had little doubt that I had come to the end of my career when I perceived the somewhat sinister figure of the late Professor Moriarty standing upon the narrow pathway which led to safety.  I read an inexorable purpose in his gray eyes.  I exchanged some remarks with him, therefore, and obtained his courteous permission to write the short note which you afterwards received.  I left it with my cigarette-box and my stick, and I walked along the pathway, Moriarty still at my heels.  When I reached the end I stood at bay.  He drew no weapon, but he rushed at me and threw his long arms around me.  He knew that his own game was up, and was only anxious to revenge himself upon me.  We tottered together upon the brink of the fall.  I have some knowledge, however, of baritsu, or the Japanese system of wrestling, which has more than once been very useful to me.  I slipped through his grip, and he with a horrible scream kicked madly for a few seconds, and clawed the air with both his hands.  But for all his efforts he could not get his balance, and over he went.  With my face over the brink, I saw him fall for a long way.  Then he struck a rock, bounded off, and splashed into the water.”

I listened with amazement to this explanation, which Holmes delivered between the puffs of his cigarette.

“But the tracks!” I cried.  “I saw, with my own eyes, that two went down the path and none returned.”