these people would be compelled to place his very face against
the glass before he could be seen. There is a three-foot flower-
border outside this window, but no indication of a footmark. It
is difficult to imagine, then, how an outsider could have made so
terrible an impression upon the company, nor have we found any
possible motive for so strange and elaborate an attempt. You
perceive our difficulties, Watson?"

"They are only too clear," I answered with conviction.

"And yet, with a little more material, we may prove that they are
not insurmountable," said Holmes. "I fancy that among your
extensive archives, Watson, you may find some which were nearly
as obscure. Meanwhile, we shall put the case aside until more
accurate data are available, and devote the rest of our morning
to the pursuit of neolithic man."

I may have commented upon my friend's power of mental detachment,
but never have I wondered at it more than upon that spring
morning in Cornwall when for two hours he discoursed upon celts,
arrowheads, and shards, as lightly as if no sinister mystery were
waiting for his solution. It was not until we had returned in
the afternoon to our cottage that we found a visitor awaiting us,
who soon brought our minds back to the matter in hand. Neither
of us needed to be told who that visitor was. The huge body, the
craggy and deeply seamed face with the fierce eyes and hawk-like
nose, the grizzled hair which nearly brushed our cottage ceiling,
the beard--golden at the fringes and white near the lips, save
for the nicotine stain from his perpetual cigar--all these were
as well known in London as in Africa, and could only be