“Not unaccountable!  What do you mean?  Such a thing has never occurred since the birth of the world.  I know not what to think, Hammond.  God grant that I am not mad, and that this is not an insane fantasy!”

“Let us reason a little, Harry.  Here is a solid body which we touch, but which we cannot see.  The fact is so unusual that it strikes us with terror.  Is there no parallel, though, for such a phenomenon?  Take a piece of pure glass.  It is tangible and transparent.  A certain chemical coarseness is all that prevents its being so entirely transparent as to be totally invisible.  It is not theoretically impossible, mind you, to make a glass which shall not reflect a single ray of light,—­a glass so pure and homogeneous in its atoms that the rays from the sun will pass through it as they do through the air, refracted but not reflected.  We do not see the air, and yet we feel it.”

“That’s all very well, Hammond, but these are inanimate substances.  Glass does not breathe, air does not breathe. This thing has a heart that palpitates,—­a will that moves it,—­lungs that play, and inspire and respire.”

“You forget the phenomena of which we have so often heard of late,” answered the Doctor, gravely.  “At the meetings called ‘spirit circles,’ invisible hands have been thrust into the hands of those persons round the table,—­warm, fleshly hands that seemed to pulsate with mortal life.”

“What?  Do you think, then, that this thing is——­”

“I don’t know what it is,” was the solemn reply; “but please the gods I will, with your assistance, thoroughly investigate it.”

We watched together, smoking many pipes, all night long, by the bedside of the unearthly being that tossed and panted until it was apparently wearied out.  Then we learned by the low, regular breathing that it slept.

The next morning the house was all astir.  The boarders congregated on the landing outside my room, and Hammond and myself were lions.  We had to answer a thousand questions as to the state of our extraordinary prisoner, for as yet not one person in the house except ourselves could be I induced to set foot in the apartment.

The creature was awake.  This was evidenced by the convulsive manner in which the bedclothes were moved in its efforts to escape.  There was something truly terrible in beholding, as it were, those second-hand indications of the terrible writhings and agonized struggles for liberty which themselves were invisible.

Hammond and myself had racked our brains during the long night to discover some means by which we might realize the shape and general appearance of the Enigma.  As well as we could make out by passing our hands over the creature’s form, its outlines and lineaments were human.  There was a mouth; a round, smooth head without hair; a nose, which, however, was little elevated above the cheeks; and its hands and feet felt like those of a boy.  At first we thought of placing the being on a smooth surface and tracing its outlines with chalk, as shoemakers trace the outline of the foot.  This plan was given up as being of no value.  Such an outline would give not the slightest idea of its conformation.