of the
secret between Mrs. Heredith and Nepcote.

"Your confidence is quite safe with me, Tufnell," the detective added
after a pause. "But I cannot answer your question at present."

"Very well, sir." The butler turned to the sideboard again without
further remark, and left the dining-room a few minutes later.

Colwyn went to his room shortly afterwards, and occupied himself for a
couple of hours in going through his notes of the case. It was his
intention to defer his visit to the bedroom in the left wing until the
household had retired, so as to be free from the curious speculations
and tittle-tattle of the servants.

The moat-house kept country hours, and when he had finished his writing
and descended from his room he found the ground floor in darkness. A
clock somewhere in the stillness chimed solemnly as he walked swiftly
across the hall. Its strokes finished proclaiming the hour of eleven as
he mounted the staircase of the left wing.

The loneliness of the deserted wing was like a moving shuddering thing
in the desolation of the silence and the darkness. It was as though the
echoing corridor and the empty rooms were whispering, with the appeal of
the forgotten, for friendly human companionship and light to disperse
the horror of sinister shapes and brooding shadows which lurked in the
abode of murder. Colwyn entered the bedroom where Mrs. Heredith had been
murdered, and by the ray of his electric torch crossed to the bedside
and switched on the light.

He stood there motionless for a while, trying to picture the manner and
the method of the murder. If Hazel Rath had spoken the truth, the
murderer had stood where he was now standing when the girl entered the
room in the darkness. Had the light from the corridor, streaming through
the open door, revealed her approaching figure to him? How long had he
been there in the darkness, waiting for the moment to kill the woman on
the bed?

If Nepcote was the murderer he must have entered almost immediately
before, because he could not have reached the moat-house until nearly
half-past seven, and the shot was fired at twenty minutes to eight. How
had he known that Mrs. Heredith was there alone, in the darkness? A
secret assignation might have been the explanation if the time had been
after, instead of before the household's departure for the evening. But
even the most wanton pair of lovers would hesitate to indulge their
passion while the risk of chance discovery an