He heard nothing.
But the eerie feeling that he was watched grew upon him.

Presently he fancied that the darkness began to vibrate, as if an electrical current of some sort were being passed through it, and it might forthwith burst into light.

Cleggett, as we know, was not easily frightened.

But now he was possessed of a strange feeling, akin to terror, but which was at the same time not any terror of physical injury.

He did not fear Loge; in dark or daylight he was ready to grapple with him and fight it out; nevertheless he feared.