Stealth mission to explore the surrounding points of interest

The party discovered the water north of camp was unnaturally oily and viscous, encountered eerie green creatures. Spirits pointed toward a great tree with a cave nearby — the likely source of the river's magical taint.

Recap

Some people from the expedition were getting water from the nearby river and got spooked away. We checked it out and the river had a weird shine and viscosity to it. We met some Chwingas (tiny fey forest spirits), but they got spooked away by some tainted versions of Chwingas that appeared and summoned both an Earth Elemental and a Water Elemental. The Chwingas seemed to resist our physical attacks, but we managed to dispatch them and the elementals. After the fight, the original Chwingas showed back up and pointed out a massive tree deeper in the forest. They seemed very eager for us to go there. We also saw a cave that the river was flowing out of not too far from the tree. The Chwingas seemed to indicate that this place was bad/dangerous, but liked the prospect of us checking it out. On the way back to camp, we saw some fog had cleared near the cliffs and noticed a very large cave mouth in the cliffside.