This was as much as the young detective could expect, and having expressed his thanks, he took his leave in anything but a discontented frame of mind.  With so powerful an advocate as the doctor, he felt confident that he should soon be able to conquer this young girl’s reticence and learn all that was to be learned from any one but Mr. Brotherson himself.  In the time which must elapse between that happy hour and the present, he would circulate and learn what he could about the prospective manager.  But he soon found that he could not enter the Works without a permit, and this he was hardly in a position to demand; so he strolled about the village instead, and later wandered away into the forest.

Struck by the inviting aspect of a narrow and little used road opening from the highway shortly above the house where his interests were just then centred, he strolled into the heart of the spring woods till he came to a depression where a surprise awaited him, in the shape of a peculiar structure rising from its midst where it just fitted, or so nearly fitted that one could hardly walk about it without brushing the surrounding tree trunks.  Of an oval shape, with its door facing the approach, it nestled there, a wonder to the eye and the occasion of considerable speculation to his inquiring mind.  It had not been long built, as was shown very plainly by the fresh appearance of the unpainted boards of which it was constructed; and while it boasted of a door, as I’ve already said, there were no evidences visible of any other break in the smooth, neatly finished walls.  A wooden ellipse with a roof but no windows; such it appeared and such it proved to be.  A mystery to Sweetwater’s eyes, and like all mysteries, interesting.  For what purpose had it been built and why this isolation?  It was too flimsy for a reservoir and too expensive for the wild freak of a crank.

A nearer view increased his curiosity.  In the projection of the roof over the curving sides he found fresh food for inquiry.  As he examined it in the walk he made around the whole structure, he came to a place where something like a hinge became visible and further on another.  The roof was not simply a roof; it was also a lid capable of being raised for the air and light which the lack of windows necessitated.  This was an odd discovery indeed, giving to the uncanny structure the appearance of a huge box, the cover of which could be raised or lowered at pleasure.  And again he asked himself for what it could be intended?  What enterprise, even of the great Works, could demand a secrecy so absolute that such pains as these should be taken to shut out all possibility of a prying eye.  Nothing in his experience supplied him with an answer.

He was still looking up at these hinges, with a glance which took in at the same time the nearness and extreme height of the trees by which this sylvan mystery was surrounded, when a sound from the road on the opposite side of the hollow brought his conjectures to a standstill and sent him hurrying on to the nearest point from which that road became visible.