of the door. The
influence that had destroyed the harmonious conditions of the room had
apparently moved in advance of its cause. Clearly, something was about
to happen.

For the first time that night John Silence hesitated; the thought of
that dark narrow hall-way, choked with fog, and destitute of human
comfort, was unpleasant. He became aware of a faint creeping of his
flesh. He knew, of course, that the actual opening of the door was not
necessary to the invasion of the room that was about to take place,
since neither doors nor windows, nor any other solid barriers could
interpose an obstacle to what was seeking entrance. Yet the opening of
the door would be significant and symbolic, and he distinctly shrank
from it.

But for a moment only. Smoke, turning with a show of impatience,
recalled him to his purpose, and he moved past the sitting, watching
creature, and deliberately opened the door to its full width.

What subsequently happened, happened in the feeble and flickering light
of the solitary candle on the mantlepiece.

Through the opened door he saw the hall, dimly lit and thick with fog.
Nothing, of course, was visible--nothing but the hat-stand, the African
spears in dark lines upon the wall and the high-backed wooden chair
standing grotesquely underneath on the oilcloth floor. For one instant
the fog seemed to move and thicken oddly; but he set that down to the
score of the imagination. The door had opened upon nothing.

Yet Smoke apparently thought otherwise, and the deep growling of the
collie from the mat at the back of the room seemed to confirm his
judgment.

For, proud and self-possessed, the cat had again risen to his feet, and
having advanced to the door, was now ushering some one slowly into the
room. Nothing could have been more evident. He paced from side to side,
bowing his little head with great _empressement_ and holding his
stiffened tail aloft like a flag-staff. He turned this way and that,
mincing to and fro, and showing signs of supreme satisfaction. He was in
his element. He welcomed the intrusion, and apparently reckoned that his
companions, the doctor and the dog, would welcome it likewise.

The Intruder had returned for a second attack.

Dr. Silence moved slowly backwards and took up his position on the
hearthrug, keying himself up to a condition of concentrated attention.

He noted that Flame stood beside him, facing the room, with body
motionless, and head moving swiftly