ened much longer. They will therefore
probably make another attempt to-night."

"It seems likely," I replied; and was silent. Outside the open
windows whispered the shrubbery, as a soft breeze stole through the
bushes. Beyond, the moon made play in the dim avenue. From the
old chapel hard by the sweet-toned bell proclaimed midnight. Our
vigil was begun. In this room it was that Professor Deeping had
met death at the hands of the murderous Easterns; here it was that
Marden and West had mysteriously been struck down the night before.

To-night was every whit as hot, and Bristol and I had the windows
widely opened. My companion was seated where the detective, Marden,
had sat, in a chair near the westerly window, and I lay back in
the armchair that had been occupied by West.

I may repeat here that the house of the late Professor Deeping was
more properly a cottage, surrounded by a fairly large piece of
ground, for the most part run wild. The room used as a study was
on the ground floor, and had windows on the west and on the south.
Those on the west (French windows) opened on a loggia; those on the
south opened right into the dense tangle of a neglected shrubbery.
The place possessed an oppressive atmosphere of loneliness, for
which in some measure its history may have been responsible.

The silence, seemingly intensified by each whisper that sped through
the elms and crept about the shrubbery, grew to such a stillness
that I told myself I had experienced nothing like it since crossing
with a caravan I had slept in the desert. Yet noisy, whirling
London was within gunshot of us; and this, though hard enough to
believe, was a reflection oddly comforting. Only one train of
thought was possible, and this I pursued at random.

By what means were Marden and West struck down? In thus exposing
ourselves, in order that we might trap the author or authors of the
outrage, did we act wisely?

"Bristol," I said suddenly, "it was someone who came through the
open window."

"No one," he replied, "came through the windows. West saw
absolutely nothing. But if any one comes that way to-night, we
have him!"

"West may have seen nothing; but how else could any one enter?"

Bristol offered no reply; and I plunged again into a maze of
speculation.

Powerful mantraps were set in such a way that any one or anything,
ignorant of their positions, coming up to the windows must
unavoidably be snared. These had been placed