Vortex!

'Burble! Burble!'

The pounding and the thrashing of the water slamming on the moss-covered granite rock suppressed all the other sounds of the forest. Removing a huge leaf from a Pine tree, Aylin walked forward in the direction of the waterfall. Dan, Liam and Zion followed her too, but their eyes were combing the surroundings to find any kind of clue.

Liam and Zion stopped abruptly in the middle of their way as a weird kind of stone grabbed their attention. A stone was covered with some kind of sticky and green liquid. The liquid looked like glue. 

Liam suddenly bent down and picked up a little of that weird liquid. While sniffing the sharp and strong smell of that weird liquid, Liam complained, wrinkling his nose with a disgusted expression, "Eww! It smells so bad. What the hell is this!"