No one could get into the town house without her noticing at once, but that 
isn’t what draws her to her feet again. It’s the character of the air, which
takes on the color of what she’s doing and thinking. If Tikki just lies around,
the air takes on a lax quality. If she’s up and moving, looking, listening,
testing the air, the atmosphere assumes a wary character, a scent like 
vigilance, suggestive of muscle like spring-loaded steel, of a strength and 
power that few creatures in the world would dare to confront.