I was surprised.  I waited until she had had time to get almost to the house before I started.  And then I stepped back again into the shadows.  The reason why Gertrude had not kept her tryst was evident.  Leaning on the parapet of the bridge in the moonlight, and smoking a pipe, was Alex, the gardener.  I could have throttled Liddy for her carelessness in reading the torn note where he could hear.  And I could cheerfully have choked Alex to death for his audacity.

But there was no help for it:  I turned and followed Gertrude slowly back to the house.

The frequent invasions of the house had effectually prevented any relaxation after dusk.  We had redoubled our vigilance as to bolts and window-locks but, as Mr. Jamieson had suggested, we allowed the door at the east entry to remain as before, locked by the Yale lock only.  To provide only one possible entrance for the invader, and to keep a constant guard in the dark at the foot of the circular staircase, seemed to be the only method.

In the absence of the detective, Alex and Halsey arranged to change off, Halsey to be on duty from ten to two, and Alex from two until six.  Each man was armed, and, as an additional precaution, the one off duty slept in a room near the head of the circular staircase and kept his door open, to be ready for emergency.

These arrangements were carefully kept from the servants, who were only commencing to sleep at night, and who retired, one and all, with barred doors and lamps that burned full until morning.

The house was quiet again Wednesday night.  It was almost a week since Louise had encountered some one on the stairs, and it was four days since the discovery of the hole in the trunk-room wall.

Arnold Armstrong and his father rested side by side in the Casanova churchyard, and at the Zion African Church, on the hill, a new mound marked the last resting-place of poor Thomas.

Louise was with her mother in town, and, beyond a polite note of thanks to me, we had heard nothing from her.  Doctor Walker had taken up his practice again, and we saw him now and then flying past along the road, always at top speed.  The murder of Arnold Armstrong was still unavenged, and I remained firm in the position I had taken—­to stay at Sunnyside until the thing was at least partly cleared.

And yet, for all its quiet, it was on Wednesday night that perhaps the boldest attempt was made to enter the house.  On Thursday afternoon the laundress sent word she would like to speak to me, and I saw her in my private sitting-room, a small room beyond the dressing-room.

Mary Anne was embarrassed.  She had rolled down her sleeves and tied a white apron around her waist, and she stood making folds in it with fingers that were red and shiny from her soap-suds.

“Well, Mary,” I said encouragingly, “what’s the matter?  Don’t dare to tell me the soap is out.”