The Adamantine Mastersmith

Expedition

Three Wardens come to the aid of Mastersmith Sollyn of the famous Adamantine Halls, whose home has been overrun by Duergar.

Sage informs Thessalia, Gringnir, and Morthos that a dwarven Mastersmith known as Sollyn has put in a request for aid, because he's heard that Gringnir has been asking after a smith. It turns out her home was overrun by duergar a few days ago.
The Wardens hire a guide, Aiden Vallar, who ends up being absolutely useless, but does lead them past a ritual site involving mammoths and a strange site known as the Heart of Winter. Eventually the party finds their way to their destination, the Adamantine Halls. Therein, they overcome the earth elemental guardians, find a thief named Sarin trapped in a rune circle (she temporarily joins the party before stealing 100 GP from each of them and leaving them), fight the duergar, and destroy the tunnel they used to gain access.