In one of these momentary lulls of the wind, there came a sharp, distinct knocking on the window-pane.

He remembered with a thrill the old story of the supernatural hand which had troubled that house, and began its pranks at this very window.
Ay, ay, 'twas the impatient rapping of a knuckle on the glass quite indisputably.
It is all very well weaving the sort of dream or poem with which Mervyn was half amusing and half awing himself, but the sensation is quite different when a questionable sound or sight comes uninvited to take the matter out of the province of our fancy and the control of our will.
Mervyn found himself on his legs, and listening in a less comfortable sort of horror, with his gaze fixed in the direction of that small sharp knocking.

But the storm was up again, and drowning every other sound in its fury.
If Mr.Mervyn had been sufficiently frightened, he would have forthwith made good his retreat to his bed-room, or, if he had not been frightened at all, he would have kept his seat, and allowed his fancies to return to their old channel.

But, in fact, he took a light in his hand, and opened a bit of the window-shutter.

The snow, however, was spread over the panes in a white, sliding curtain, that returned the light of his candle, and hid all without.