That was my reconstructed theory of that afternoon and evening: it was almost correct—not quite.
There was a telegram that morning from Gertrude.
“Halsey conscious and improving. Probably home in day or so. GERTRUDE.”
With Halsey found and improving in health, and with at last something to work on, I began that day, Thursday, with fresh courage. As Mr. Jamieson had said, the lines were closing up. That I was to be caught and almost finished in the closing was happily unknown to us all.
It was late when I got up. I lay in my bed, looking around the four walls of the room, and trying to imagine behind what one of them a secret chamber might lie. Certainly, in daylight, Sunnyside deserved its name: never was a house more cheery and open, less sinister in general appearance. There was not a corner apparently that was not open and above-board, and yet, somewhere behind its handsomely papered walls I believed firmly that there lay a hidden room, with all the possibilities it would involve.
I made a mental note to have the house measured during the day, to discover any discrepancy between the outer and inner walls, and I tried to recall again the exact wording of the paper Jamieson had found.
The slip had said “chimney.” It was the only clue, and a house as large as Sunnyside was full of them. There was an open fireplace in my dressing-room, but none in the bedroom, and as I lay there, looking around, I thought of something that made me sit up suddenly. The trunk-room, just over my head, had an open fireplace and a brick chimney, and yet, there was nothing of the kind in my room. I got out of bed and examined the opposite wall closely. There was apparently no flue, and I knew there was none in the hall just beneath. The house was heated by steam, as I have said before. In the living-room was a huge open fireplace, but it was on the other side.
Why did the trunk-room have both a radiator and an open fireplace? Architects were not usually erratic! It was not fifteen minutes before I was up-stairs, armed with a tape-measure in lieu of a foot-rule, eager to justify Mr. Jamieson’s opinion of my intelligence, and firmly resolved not to tell him of my suspicion until I had more than theory to go on. The hole in the trunk-room wall still yawned there, between the chimney and the outer wall. I examined it again, with no new result. The space between the brick wall and the plaster and lath one, however, had a new significance. The hole showed only one side of the chimney, and I determined to investigate what lay in the space on the other side of the mantel.