f that I have no doubt
at all.

"But the gunshot was apparently the cause of death. Therefore the shot
must have been fired some time earlier than we are told. But there
could be no mistake about such a matter as that. We are in the
presence, therefore, of a deliberate conspiracy upon the part of the
two people who heard the gunshot--of the man Barker and of the woman
Douglas. When on the top of this I am able to show that the blood mark
on the windowsill was deliberately placed there by Barker, in order to
give a false clue to the police, you will admit that the case grows
dark against him.

"Now we have to ask ourselves at what hour the murder actually did
occur. Up to half-past ten the servants were moving about the house; so
it was certainly not before that time. At a quarter to eleven they had
all gone to their rooms with the exception of Ames, who was in the
pantry. I have been trying some experiments after you left us this
afternoon, and I find that no noise which MacDonald can make in the
study can penetrate to me in the pantry when the doors are all shut.

"It is otherwise, however, from the housekeeper's room. It is not so
far down the corridor, and from it I could vaguely hear a voice when it
was very loudly raised. The sound from a shotgun is to some extent
muffled when the discharge is at very close range, as it undoubtedly
was in this instance. It would not be very loud, and yet in the silence
of the night it should have easily penetrated to Mrs. Allen's room. She
is, as she has told us, somewhat deaf; but none the less she mentioned
in her evidence that she did hear something like a door slamming half
an hour before the alarm was given. Half an hour before the alarm was
given would be a quarter to eleven. I have no doubt that what she heard
was the report of the gun, and that this was the real instant of the
murder.

"If this is so, we have now to determine what Barker and Mrs. Douglas,
presuming that they are not the actual murderers, could have been doing
from quarter to eleven, when the sound of the shot brought them down,
until quarter past eleven, when they rang the bell and summoned the
servants. What were they doing, and why did they not instantly give the
alarm? That is the question which faces us, and when it has been
answered we shall surely have gone some way to solve our problem."

"I am convinced myself," said I, "that there is an understanding
between those two people. She must be a he