“Fighting so many at once is a dangerous prospect, unless you are a truly mighty warrior. This many so close together suggests a nest nearby - if we find it and destroy it, we might have better luck.”— Waking Cloud
From Pine Creek, the Courier can either enter the nearby cave to set explosives and close off the entrance, or kill the yao guai outside the cave. The cave option does not require combat. Completion of either option ends the quest successfully, and the particular method chosen has no effect on the rest of the game.
If opting to collapse the cave entrance, the player character enters the cave. From here, they may then explore the cave, looking for each of three marked positions on the floor where the player character must place the explosives. The "mining explosives" are not "items" carried by the player character; instead, They are a part of the cave and only need to be enabled. They are visually identical to C-4 plastic explosive.
There are three yao guai in a central area of the cave, but killing them is not a requirement for this quest as they can be avoided while "placing the explosives." When all three explosives are set, the Courier should exit the cave and trigger the mining detonator, sealing the cave and completing the quest.
If the Courier chooses to kill the yao guai outside the cave, they can simply follow the map markers to the targets and dispatch them. Once all of the target yao guai are killed, the quest is complete.
Quest stages
Stage
Status
Description
10
Deal with the yao guai at Pine Creek.
35
Optional: Collapse the yao guai cave
36
Plant mining explosives at key points within the cave.
37
Leave the cave and set off the charges with the mining detonator.
38
Optional: Kill the yao guai at Pine Creek.
Notes
Even if the Courier kills the yao guai in the cave before this quest, they may respawn. If they did not, the only way to complete the quest is to plant the explosives.
Look closely for the charge markers, as they blend in with the cave floor making them difficult to see in the dark.
If the player character plants the explosives in the cave without triggering them, and then kills the yao guai at Pine Creek, the quest will be compromised and can not be completed.
Waking Cloud will comment that it is very dangerous to directly attack the yao guai at Pine Creek. You can reassure her, but she will be skeptical.
Once you set off the explosives, you cannot enter the cave again.
It is possible to complete both optional parts of the quest, but it requires good timing. As you kill the third and final yao guai, you can quickly switch to the detonator and collapse the cave (assuming you placed the C4 previously). However, this will not give you any extra rewards.