dense

At the other end, silent, scarcely visible, and like a shadow, was a sentinel, who was walking up and down before a grotto, which was only distinguishable because in that spot the darkness seemed more dense than elsewhere.

As we watched it the fog-wreaths came crawling round both corners of the house and rolled slowly into one dense bank on which the upper floor and the roof floated like a strange ship upon a shadowy sea.

So as the fog-bank flowed onward we fell back before it until we were half a mile from the house, and still that dense white sea, with the moon silvering its upper edge, swept slowly and inexorably on.

Suddenly the sky seemed to him to become still darker and more dense, and heavy clouds seemed to sweep down towards him; at the same time he felt a sharp pain in his knee.