He ran
forward to the street and looked up and down, but found it empty; then
he ran back to the alley. At the end of the alley, where it
intersected the cross street, the figure of the man running away
appeared suddenly out of the shadows, then disappeared; Alan, following
as far as the street, could see nothing more of him; this street too
was empty.

He ran a little farther and looked, then he went back to the house.
The side door had swung shut again and latched. He felt in his pocket
for his key and went around to the front door. The snow upon the steps
had been swept away, probably by the servant who had come to the house
earlier in the day with Constance Sherrill, but some had fallen since;
the footsteps made in the early afternoon had been obliterated by it,
but Alan could see those he had made that evening, and the marks where
some one else had gone into the house and not come out again. In part
it was plain, therefore, what had happened: the man had come from the
south, for he had not seen the light Alan had had in the north and rear
part of the house; believing no one was in the house, the man had gone
in through the front door with a key. He had been some one familiar
with the house; for he had known about the side door and how to reach
it and that he could get out that way. This might mean no more than
that he was the same who had searched through the house before; but at
least it made his identity with the former intruder more certain.

Alan let himself in at the front door and turned on the light in the
reading lamp in the library. The electric torch still was burning on
the floor and he picked it up and extinguished it; he went up-stairs
and brought down his shoes. He had seen a wood fire set ready for
lighting in the library, and now he lighted it and sat before it drying
his wet socks before he put on his shoes. He was still shaking and
breathing fast from his struggle with the man and his chase after him,
and by the strangeness of what had taken place.

When the shaft of light from the torch had flashed across Alan's face
in the dark library, the man had not taken him for what he was--a
living person; he had taken him for a specter. His terror and the
things he had cried out could mean only that. The specter of whom?
Not of Benjamin Corvet; for one of the things Alan had remarked when he
saw Benjamin Corvet's picture was that he himself did not look at all
like his father. Besides, wha