Solution

On the middle path, follow the rock path and ignore all three rocks.

Description

Where the very earth disobeyed nature's rules, the merchant walked a fine line between life and death with every step.

Life somehow finds a way to thrive in even the harshest environs. Although this is but my own theory, I think the struggle to survive makes both flora and fauna more delicious. I tested this theory on the mushrooms that clung to rocky surfaces of the valley walls, and I stand firm in its truth, for they were exquisite. Though they had the look and feel of hard stone, they melted in my mouth like soft cream. Blessed with both a striking texture and rich flavor, the mushrooms could serve as an aromatic accent in any number of dishes.

Curious as to whether such mushrooms existed in the real world, I researched an illustrated encyclopedia and found one that looked almost identical. Imagine my surprise when the description indicated strong hallucinatory effects. Perhaps because the world inside the book is an illusion to begin with, such effects were not reproduced. Regardless, I realized anew the danger of putting unfamiliar plant life in my mouth. I was cautious enough when traversing that valley of floating rocks─I should practice that same caution when next a strange new specimen rouses my appetite.