FR-DC-WST-01: Is that a Black Dragon?!?

At the southern tip of the Wood of Sharp Teeth near Baldur's Gate, a small group of Wood Elves and Drow have established a small community amidst the trees. Druidic magic enhanced the trees here so the elves could build their homes in the treetops, and none outside their community were any the wiser of their presence, thanks to concealment magic.
In recent weeks the woods have begun to transform, as an unexpected miasma has taken hold and caused the wooded area to turn into a swamp. Scouts and hunters from the elven village set out to learn what is happening but never returned.
Desperate, the elven leaders turned to a retired adventurer they knew of in Baldur's Gate for aid, asking them to reach out to adventurers they could trust to help.

This is a Tier 1 adventure for characters level 1 to 4.

Content Warning: Body Horror, Dismemberment, Betrayal