C36 Grand Canyon

It sounded like the sound of a thumb and forefinger being blown out of the mouth, and I hastened to tell them to lower themselves.

Then the whistle sounded a few more times, but there was no movement around us.

"Shh!" Duan Long spoke to us: "We didn't seem to have been discovered!"

We all nodded.

The whistle sounded again, and it seemed to be closer to us.

"Quick!" All of you