Wave Echo Cave

Gundren, delighted to know that his map had been recovered explained to the party that the location of the mines were lost five hundred years ago during orc invasions that devastated the area, located a days walk from Phandalin. In the centuries since, countless prospectors and adventurers have searched for the lost mine, but none succeeded until the Rockseeker brothers found the entrance a month ago. Unfortunately, the Rockseekers did not realize they were being trailed by spies working for Nezznar, the Black Spider, and they inadvertently led the drow villain to the Forge of Spells.
 
The Black Spider had killed both Gundren's brother and cousin in order to take the mine's secrets for himself, but Gundren does not want their deaths to be in vein. He gave the party the map and asked them to bring The Black Spider to justice. Sildar echoed his friend's wishes and asked the group to bring Nezznar here alive.
 
Following Gundren Rockseeker's map to the lost mine, the party discovers the cavern is now overrun by undead and strange monsters. It is clear the drow is searching for the Forge of Spells but his search has been hindered by the many creatures living inside.
 
Soon, they catch up to him and his loyalest followers. A battle ensues, raging down many of the maze-like caverns of the mines until it spills out onto a rocky outcrop that descends into a massive crater. There is an old narrow bridge suspended over it and eventually the party fights The Black Spider over it. He is pushed from the cavern and falls down onto the hard rocks below.
 
Amazingly, he is not dead, but barely alive. He agrees to be put on trail, as per Sildar's wishes but Vogen, Gobnak and Arvard are adamant that he must die here. Despite Opal and Barry's objections, Arvard strikes out and decapitates The Black Spider before the rest of his party. Opal screams at her party member's, exclaiming that this is vigilantism, not justice. Vogen bags his head and sighs that not everyone can be brought to justice.
 
The group ventures home and shows Sildar the head. Disappointed, yet relieved it is over, Sildar accepts the Black Spider's death and rewards the adventurers handsomely.
 
Opal is allowed to keep Glasstaff's Staff of Defense and the Black Spider's Spider Staff.