River Monsters

River Monsters is a side quest in the Fallout: New Vegas add-on, Honest Hearts.

Quick walkthrough

 * 1) Deal with the yao guai at Pine Creek.
 * 2) Optional: Kill the yao guai at Pine Creek.
 * 3) Optional: Collapse the yao guai cave by planting explosives.

Detailed walkthrough
Make your way to Pine Creek. You can either take the fast and easy way out, and kill the yao guai or you can take the longer route and blow up the yao guai cave by placing explosives in positions marked on the cave floor. The first option is more combat heavy as you will be facing half a dozen or so yao guai in open combat. In the cave there are only three yao guai but in close quarters. However, if you are a stealth character it will be very easy to complete the quest undetected. Either way finishes the quest.

Bugs

 * If you chose to blow the yao guai cave, after you set up the explosives, outside you will equip a special detonator. Changing the detonator with some other weapon from this point, sometimes you will not have the possibility to bring back the detonator, therefore forcing you to continue by taking the road to the three bears to complete the side-quest. Having a detonator in your inventory will not allow you to make the charges go off.