yer, he had
gone across to the railroad embankment, and, by jumping in front of the
car, had caused Halsey to swerve. The rest of the story we knew.

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