From publisher blurb:
5th Edition Mini-Dungeon for four characters of level 6
There were signs. There were portents. And there was one skilled enough to read them.
In an unimaginably ancient past, the lizardfolk archmage Botinqah looked to the heavens, and there she saw the end of her world. And so, on the day the fires fell, the day the skies cracked open and doom came for the first children of the gods, the mighty Botinqah saved what she could. With her dying effort, she managed to preserve one small fragment of her homeland against the ravages of the Skyfall, concealing a secluded mountain valley within a magical subterranean refuge.
Eons have passed. Now that sliver of primeval wilderness is about to meet the modern world, and the two may prove uneasy neighbors.