n hearing the sound of the quarrel she descended and
returned with the other servants. On that first occasion, when she was
alone, she says that the voices of her master and mistress were sunk
so low that she could hear hardly anything, and judged by their tones
rather than their words that they had fallen out. On my pressing her,
however, she remembered that she heard the word David uttered twice by
the lady. The point is of the utmost importance as guiding us towards
the reason of the sudden quarrel. The Colonel's name, you remember, was
James.

"There was one thing in the case which had made the deepest impression
both upon the servants and the police. This was the contortion of the
Colonel's face. It had set, according to their account, into the most
dreadful expression of fear and horror which a human countenance is
capable of assuming. More than one person fainted at the mere sight
of him, so terrible was the effect. It was quite certain that he had
foreseen his fate, and that it had caused him the utmost horror. This,
of course, fitted in well enough with the police theory, if the Colonel
could have seen his wife making a murderous attack upon him. Nor was
the fact of the wound being on the back of his head a fatal objection to
this, as he might have turned to avoid the blow. No information could
be got from the lady herself, who was temporarily insane from an acute
attack of brain-fever.

"From the police I learned that Miss Morrison, who you remember went out
that evening with Mrs. Barclay, denied having any knowledge of what it
was which had caused the ill-humor in which her companion had returned.

"Having gathered these facts, Watson, I smoked several pipes over them,
trying to separate those which were crucial from others which were
merely incidental. There could be no question that the most distinctive
and suggestive point in the case was the singular disappearance of the
door-key. A most careful search had failed to discover it in the room.
Therefore it must have been taken from it. But neither the Colonel
nor the Colonel's wife could have taken it. That was perfectly clear.
Therefore a third person must have entered the room. And that third
person could only have come in through the window. It seemed to me that
a careful examination of the room and the lawn might possibly reveal
some traces of this mysterious individual. You know my methods, Watson.
There was not one of them which I did not apply to th