From the publisher's website:
In the rural Menador Mountains of southern Nidal, the PCs find themselves in a fog-enshrouded mining town facing a terrible fate. Silver Tarn, on the banks of which the settlement of Stom's Claim stands, has grown a mind of its own. Reaching out with strange abominations of the deep to siphon the souls of the stubborn populace, the lake hopes to release a powerful fiend bound centuries earlier by Arodenite clerics. If the PCs can't stop the Silver Tarn Entity, Stom's Claim and much of western Avistan may soon fall to a fate beyond comprehension.
A Pathfinder Society Scenario designed for 7th to 11th level characters (Tiers: 7-8 and 10-11).
This scenario is designed for play in Pathfinder Society Organized Play, but can easily be adapted for use with any world. This scenario is compliant with the Open Game License (OGL) and is suitable for use with the Pathfinder Roleplaying Game.