and so inflicted a wound which must have caused instantaneous death.
Such were the circumstances of the Park Lane Mystery, which were further
complicated by entire absence of motive, since, as I have said, young
Adair was not known to have any enemy, and no attempt had been made to
remove the money or valuables in the room.

All day I turned these facts over in my mind, endeavouring to hit upon
some theory which could reconcile them all, and to find that line
of least resistance which my poor friend had declared to be the
starting-point of every investigation. I confess that I made little
progress. In the evening I strolled across the Park, and found myself
about six o'clock at the Oxford Street end of Park Lane. A group of
loafers upon the pavements, all staring up at a particular window,
directed me to the house which I had come to see. A tall, thin man with
coloured glasses, whom I strongly suspected of being a plain-clothes
detective, was pointing out some theory of his own, while the others
crowded round to listen to what he said. I got as near him as I could,
but his observations seemed to me to be absurd, so I withdrew again in
some disgust. As I did so I struck against an elderly, deformed man,
who had been behind me, and I knocked down several books which he was
carrying. I remember that as I picked them up, I observed the title
of one of them, THE ORIGIN OF TREE WORSHIP, and it struck me that the
fellow must be some poor bibliophile, who, either as a trade or as a
hobby, was a collector of obscure volumes. I endeavoured to apologize
for the accident, but it was evident that these books which I had so
unfortunately maltreated were very precious objects in the eyes of their
owner. With a snarl of contempt he turned upon his heel, and I saw his
curved back and white side-whiskers disappear among the throng.

My observations of No. 427 Park Lane did little to clear up the problem