When I first became aware of the howling of distant dogs I know not; but it was with a great start that I was aroused from my semi-reverie by the ringing of the door-bell.  I realized that I had sat much longer than I had supposed.  It was a quarter to one.

Gatton was my first thought; there must be an unexpected development in the case calling in some way for my services.  Coates was a sound sleeper and evidently had not been awakened by the ringing of the bell; therefore, arrayed as I was in pajamas, slippers and bath-robe (for this, during the hot weather was my indoor costume) I walked out along the little corridor, unbolted the front door and opened it.

A woman stood there.

For a moment I thought foolishly that it was Isobel, and my heart gave a great leap.  But the delusion was instantly dispelled when my visitor spoke.

Her voice had a totally different tone from that of Isobel—­it was a low, almost caressing voice, with a vaguely husky note in it, fascinating in a way, yet although I found myself unable to account for the fact, vaguely uncanny—­queer.

“Please excuse me,” she said.  “You will naturally wonder what has brought a visitor to your door at this hour of the night, and indeed my explanation is a strange one.”

She glanced apprehensively over her shoulder as she spoke, out into the darkness of the roadway.  I observed that she was apparently in evening dress and wore a very handsome cloak, having a thick silk scarf so draped about her head and shoulders that her face was quite concealed.  Very clearly, now, I could hear the howling of dogs.

Instinct is a curious thing, and that which it prompted me to do at the moment when I found myself confronting this strange woman was promptly to awaken Coates!  Honestly I was afraid of her and wished for nothing better than to have the closed door between us.  This was all the more unaccountable as she had the appearance and manners of a cultured woman, presenting indeed a figure of great elegance as she stood there with her tall slender form outlined by the moonlight which slanted down through the trees to form a scimitar of light upon the path behind her.

Of course I could never have acted upon this singular instinct, but the decision was taken out of my hands; for suddenly my visitor uttered a low cry of fear, swayed dizzily and seemed about to fall.

Perforce I stepped forward to support her and before I knew what had happened, she had tottered into the passage, resting heavily upon my shoulder.

“Close the door!” she said in that low husky voice.  “Quick!  Quick!  I have seen them again!”

An unpleasant chill communicated itself to me.

“The eyes!” she whispered.  “Two great eyes have followed me!  That was why I knocked at your door.  I was afraid.”

It was enough, the mention of two great eyes.  Leaving my visitor temporarily to take care of herself, I sprang to the door and closed it hurriedly.  As I turned, in the light from the partly open study door I saw the woman walking slowly ahead of me.  I overtook her, holding the door fully open for her to pass in.