theories of relativity
and intra-atomic action. One might easily imagine an alien nucleus of
substance or energy, formless or otherwise, kept alive by imperceptible
or immaterial subtractions from the life-force or bodily tissue and
fluids of other and more palpably living things into which it penetrates
and with whose fabric it sometimes completely merges itself. It might be
actively hostile, or it might be dictated merely by blind motives of
self-preservation. In any case such a monster must of necessity be in
our scheme of things an anomaly and an intruder, whose extirpation forms
a primary duty with every man not an enemy to the world's life, health,
and sanity.

What baffled us was our utter ignorance of the aspect in which we might
encounter the thing. No sane person had ever seen it, and few had ever
felt it definitely. It might be pure energy--a form ethereal and outside
the realm of substance--or it might be partly material; some unknown and
equivocal mass of plasticity, capable of changing at will to nebulous
approximations of the solid, liquid, gaseous, or tenuously unparticled
states. The anthropomorphic patch of mold on the floor, the form of the
yellowish vapor, and the curvature of the tree-roots in some of the old
tales, all argued at least a remote and reminiscent connection with the
human shape; but how representative or permanent that similarity might
be, none could say with any kind of certainty.

* * * * *

We had devised two weapons to fight it; a large and specially fitted
Crookes tube operated by powerful storage batteries and provided with
peculiar screens and reflectors, in case it proved intangible and
opposable only by vigorously destructive ether radiations, and a pair of
military flame-throwers of the sort used in the World War, in case it
proved partly material and susceptible of mechanical destruction--for
like the superstitious Exeter rustics, we were prepared to burn the
thing's heart out if heart existed to burn. All this aggressive
mechanism we set in the cellar in positions carefully arranged with
reference to the cot and chairs, and to the spot before the fireplace
where the mold had taken strange shapes. That suggestive patch, by the
way, was only faintly visible when we placed our furniture and
instruments, and when we returned that evening for the actual vigil. For
a moment I half doubted that I had ever seen it in the more definitely
limned form