Upon accepting the quest, both "Leave No One Alive" and "Flesh Flower" will indicate that this stage is complete. The "Flesh Flower" quest completes upon talking to the coachman. The "Leave No One Alive" quest corresponds to the previous exploration of Map 1 and the Bandit Camp in Map 2.
Walk forward a few steps and you'll see a stone bridge. Jump down from the right side of the bridge. As you move forward, the person ahead will suddenly jump down. After jumping down, you can obtain a purple item.
After obtaining the purple item, turn back and head up the other side.
Once you're up, go straight and you'll see the blue-clad young master who spoke to us earlier. There's a save point on the left, materials in the upper-left corner, and books on the desk.
The book is [Meditations Miscellany #12 Lu Family Village].
