s after the passing of the autumn. The wretched man put one of
those wretched American inflictions, a hot-air furnace, in the cellar,
with huge pipes running to every room in the house--great tin
monstrosities bigger round than a man's body, ending in openings in the
wall, with what they call 'registers,' to let the heat in, or shut it
out as they please. I didn't have the wretched contrivance removed or
those blessed 'registers' plastered up. I simply had them papered over
when the rooms were done up (there's one over there near that settee),
and if a man got into this house, he could get into that furnace thing
and hide in one of those flues until he got ready to crawl up it as
easily as not. It struck me that perhaps it would be as well for you to
examine that furnace and those flues before matters go any further."

"Of course it would. Great Scott! Sir Horace, why didn't you think to
tell me of this thing before?" said Narkom, excitedly. "The fellow may
be in it at this minute. Come, show me the wretched thing."

"It's below--in the cellar. We shall have to go down the kitchen stairs,
and I haven't a light."

"Here's one," said Petrie, unhitching a bull's-eye from his belt and
putting it into Narkom's hand. "Better go with Sir Horace at once, sir.
Leave the door of the gallery open and the light on. Fish and me will
stand guard over the stuff till you come back, so in case the man is in
one of them flues and tries to bolt out at this end, we can nab him
before he can get to the windows."

"A good idea," commented Narkom. "Come on, Sir Horace. Is this the way?"

"Yes, but you'll have to tread carefully, and mind you don't fall over
anything. A good deal of my paraphernalia--bottles, retorts and the
like--is stored in the little recess at the foot of the staircase, and
my assistant is careless and leaves things lying about."

Evidently the caution was necessary, for a minute or so after they had
passed on and disappeared behind the door leading to the kitchen
stairway, Petrie and his colleagues heard a sound as of something being
overturned and smashed, and laughed softly to themselves. Evidently,
too, the danger of the furnace had been grossly exaggerated by Sir
Horace, for when, a few minutes later, the door opened and closed, and
Narkom's men, glancing toward it, saw the figure of their chief
reappear, it was plain that he was in no good temper, since his features
were knotted up into a scowl, and he swore aud