The fog that the Dementors make was completely transparent here, and she could see the distortions being made as they all floated in the air. A few of the Sarsen stones were bright amber, and Narcissa could only guess that they glowed with a type of magic she could not comprehend. The bluestones, however, appeared purple and glowed darkly as the Dementors went about rearranging them. When a bluestone got close enough to the Sarsen stone, the amber glow would seem to be smothered out by the purple. Narcissa tapped the knut communicator and whispered behind her hand, hoping to muffle the sound even more.