As you walk along the path, you'll eventually be able to see Mofang's Tree. The path continues to the right of it.
As you head up the hill to the right of the Tree, you'll find Mofang's path's only branch. Take the path to the right and keep climbing.
At the top of the climb, you'll get a surprising view — and a Steam achievement.
Head back down the path and take the turn — now on your right — to the Tree.
Take the tunnel down to the roots of the Tree and return the water just like you have three times before.
