C2064 The Reversed World?

But Pei Junlin didn't know why these birds made of withered grass could fly in the air. He had a closer look. They were indeed woven from withered grass. There were no signs of flesh and blood. However, they could flap their wings and fly freely in the air.

"There's a cave up ahead. Let's go into the cave and take a look. Maybe we can find some clues there