"The scud had banked over the moon, and it was now quite dark...."See in text(Chapter Eight)
In this image, two of the more important motifs of the story collide. The “scud” here refers to the infamous London coal-smog which, like a cloud, is occluding the moon. The pair of images—pale moon and dark smog—invites a number of pertinent metaphorical dualities: good and evil, clarity and confusion, nature and artifice. As the story hurtles towards its conclusion these opposing tensions move towards resolution.