Butler- Detecting Holly

Butler smiled again. A teenager asking for caviar. He’d never get
used to it. The smile withered on his lips halfway to the recently
remodeled entrance. A shiver passed across his heart. He knew that feeling
well. His mother had used to say that someone had just walked over his
grave. A sixth sense. Gut instinct. There was peril somewhere. Invisible,
but here nevertheless
…

Holding her breath, Holly set the DoubleDex to slow descent. She
alighted soundlessly, aiming her weapon at Butler’s chest. Now there was
a target a sun-blinded dwarf couldn’t miss.
The human couldn’t have detected her presence. Not possible. Yet
something made him pause. He stopped and sniffed the air. The Mud Man
was like a dog. No, not a dog, a wolf.
…

Holly’s eyes were level with Butler’s now, yet still more than three
feet from the ground. She released the visor seals, wincing at the
pneumatic hiss.
Butler heard the escaping gas and swung toward the source.
“Fairy,” he said. “I know you’re there. Unshield or I start shooting.”

-The Arctic Incident, Chapter 3