Horizon of Darkness

Nikta uses echolocation, trying to determine the location of the head.
“Kven, you need to tell me exactly where it is,” she asks, picking up a larger stone.

-- Oh, that’s right! -- Henry exclaimed, excited by the idea. -- What’s the distance? More than ten ? And will the Slime be able to reach it?
-- That’s a good idea! It might work! Miss Nikta, I’ll position myself right above it, just a few centimeters away; use my voice as a reference!