Thief of Time - Mouth

Two Auditors were measuring the number of atoms in a paving slab.

They looked up at a movement.

'Good afternoon,' said Lu-Tze. 'May I draw your attention to the notice my assistant is holding up?'

Susan held up the sign. It read: Mouths Must Be Open. By Order.

And Lu-Tze unfolded his hands. There was a caramel in each one, and he was a good shot. The mouths shut. The faces went impassive. Then there was a sound somewhere between a purr and a wail, which disappeared into the ultrasonic. And then... the Auditors dissolved, gently, first going fuzzy
around the edges and, as the process accelerated, swiftly becoming a spreading cloud.

'Hand-to-mouth fighting,' said Lu-Tze. 'Why doesn't it happen to humans?’

***

The Thief of Time - p306-307