darkening

For an instant I thought that it was an accident, but a moment later, looking up, I saw a man’s head against the darkening sky, and another stone struck the very ledge upon which I was stretched, within a foot of my head.

The explosion soon followed; the upper rock was lifted from its base by the terrific force of the powder; the lower one flew into pieces; thousands of insects escaped from the aperture Dantès had previously formed, and a huge snake, like the guardian demon of the treasure, rolled himself along in darkening coils, and disappeared.