A child's whistle, to be exact, slightly breathy and out of tune. He stops to listen closer, but the whistling stops too.
“Hello?” There's no reply, but all around him whispers hiss in the dark. He knows there's something there, even if he can't see it.
He sets off walking again with the same steady pace. Moments later, the whistling returns.
“Hello? Can you hear me?” He keeps walking.
The whistling stops. A child's voice replies. “Yes, sir.”
He's about to stop when the voice comes again, panicked. “Don't stop, sir. You have to keep walking.”
