The heroes found their way to the Wave Echo Cave with Gundren’s guidance. They managed to enter the cave, but discovered the remains of Gundren’s brother, Tharden, whom Regrim recognises. His boots of striding and springing were overlocked, and Regrim took them to aid him in his quest.
The group was assaulted by an ooze, before travelling down a passage that took them to a large pool. within they found a skeleton with two platinum rings and a wand of magic missiles. They avoided a room full of bugbears and saw a drow and three bugbears shifting through the rubble in a cavern, however, they snuck past, following the corridor to an ancient dwarven temple.
Here they confronted the Black Spider, a drow witch who used magic effectively. It turned out that she was an enemy of Regrim and wanted revenge, but in the end, it was Regrim who buried his axe in her breast.
In an adjacent room, they found Nundro, the third Rockseeker brother and rescued him. Afterwards, they continued to explore the mine, clearing it out so that work could resume.
Within, they found the Forge of Spells, which was guarded by flameskulls, zombies and ghouls, but chief of all a Spectator. It was clear that the Spectator wanted to avoid a fight, but a fight ensued, although half way through he considered his job done and disappeared. The forge was not as powerful as it once was, although there were several magic items to be found, Lightbringer and Dragonguard.
The final foe was a wraith wizard who had a map to a place known as Barovia.
The mines finally cleared, the group returned victorious to Phandalin, and there was much rejoicing. The Black Spider was dead, the mines could now be opened, and prosperity would return to Phandalin. Sildar Hallwinter even offered the heroes the deed to Tresendar Manor as a reward for their works, and they used the profits of the mines to have the building rebuilt.
Now the heroes could turn their attention to Lia’s curse, that they might find a cure before it was too late.