From publisher blurb:
A 5th Edition Mini-Dungeon adventure for 4 Level 3 PCs
For nearly a thousand years this mighty oak stood as monarch of the forest, with its dryad as proud steward. When a self-absorbed druid sought a new home, however, both dryad and tree became ill. This once-comfortable treetop dwelling now lies at the heart of a rotting forest. For even the greatest trees can die, going slowly bad from within.
The Blight in Your Campaign
Capricious fey, druidic circles, and elven kingdoms share something in common: They’re all concerned with the health of their forests. If any of these groups have a place in your world, then The Blight does as well. If the PCs manage to stop the spread of this dangerous fungus, then they will endear themselves to forest guardians of all kinds.