In such a tensed-up state as I cannot describe, nor, at this hour mentally reconstruct, I waited for the creaking of the stairs which should tell of the creature's descent.
I was disappointed. Removed scarce a yard from me as he was, I could hear Nayland Smith's soft, subdued breathing; but my eyes were all for the darkened hall-way, for the smudgy outline of the stair-rail with the faint patterning in the background, which, alone, indicated the wall.
It was amid an utter silence, unheralded by even so slight a sound as those which I had acquired the power of detecting--that I saw the continuity of the smudgy line of stair-rail to be interrupted.
A dark patch showed upon it, just within my line of sight, invisible to Smith on the other side of the doorway, and some ten or twelve stairs up.
No sound reached me, but the dark patch vanished--and reappeared three feet lower down.
Still I knew that this phantom approach must be unknown to my companion--and I knew that it was impossible for me to advise him of it unseen by the dreaded visitor.
A third time the dark patch--the hand of one who, ghostly, silent, was creeping down into the hall-way--vanished and reappeared on a level with my eyes. Then a vague shape became visible; no more than a blur upon the dim design of the wall-paper ... and Nayland Smith got his first sight of the stranger.
The clock on the mantelpiece boomed out the half-hour.
At that, such was my state (I blush to relate it), I uttered a faint cry!
It ended all secrecy--that hysterical weakness of mine. It might have frustrated our hopes; that it did not do so was in no measure due to me. But in a sort of passionate whirl, the ensuing events moved swiftly.
Smith hesitated not one instant. With a panther-like leap he hurled himself into the hall.
"The lights, Petrie!" he cried, "the lights! The switch is near the street door!"
I clenched my fists in a swift effort to regain control of my treacherous nerves, and, bounding past Smith, and past the foot of the stair, I reached out my hand to the switch, the situation of which, fortunately, I knew.
Around I came, in response to a shrill cry from behind me--an inhuman cry, less a cry than the shriek of some enraged animal....