Luminescent caves

The  is a vithrack commune below Stalwart mines.

Background
An outpost of vithrack from Moltuls'qu'mirr", this colony was established below the abandoned mines of Stalwart thanks to the discovery of a unique kind of spore. Its symbiotic relationship with the local spiders became a subject of interest and the vithrack soon discovered that its spores enhanced their psionic abilities. Unfortunately, it also left them susceptible to suggestion and before long, many succumbed to its control, desperate to get rid of the voice in their heads. Terenat did not partake in the frenzy and avoided being force-fed the spores until he managed to seal the spore away in the common house and hide the key. The colony degenerated into chaos, with the madness soon spreading to the mines above as the uncontrolled enhanced psionic ability resulted in vithrack randomly taking control of the people above... With disastrous consequences.

Points of interest

 * Like the miners above, the vithrack here are't quite themselves, and are searching for some sort of crystal. Throughout this area are a number of hostile Vithrack, Vithrack Brutes, Vithrack Luminaries, various dominated kith, Moon Spiders and spiderlings, and a band of Radiant Sporelings north of the start position.
 * There's a sane Vithrack named Terenat imprisoned in a holding cell in the northwest of the map. You'll have to kill the crowd outside his cell to talk to him now, but doing so sheds some light on the situation: the vithrack here found an unusual kind of Dank Spore, the spores from which at first improved their psionic abilities, but turned out to be addictive as well as allowing the (sentient) Spore to mind-control them.  The spore itself is sealed in the common room, the key to which is a crystal which Terenat has hidden in the nesting area in the south of the map.
 * There are a number of difficulty 12 Infestation of Spiders Traps strung between the pillars. Getting through this area without a fight requires a character with high stealth and mechanics.  Past the traps is a Vithrack nesting area, and the crystal key is hidden in a stash in the easternmost egg pillar.  The stash is difficult to spot - if you can't detect it, you'll need to go talk to Terenat (if you haven't already).
 * Now that you have the key, the wall of light blocking access to the common room will open for you, allowing you to go inside and confront the Radiant Spore.
 * Approaching the spore will begin a conversation. Inhaling the spores makes it possible to free the Vithrack in the room from the Spore's control so long as the Watcher has 15 Resolve or 18 Constitution, though doing so will cause concussion if the Watcher has less than 15 constitution.  Either way, there's no chance of a peaceful discussion with an evil fungus.
 * Several Radiant Sporelings will appear as the battle starts. The Radiant Spore itself is a nastier Dank Spore with an increased attack range, but the four tentacles are notable - their rock throwing targets Fortitude and can do a lot of damage to party backliners - it's best to send a tougher party member or summon closer to them in the hope of drawing their fire.  The tentacles are immune to every major status except prone and petrified.  Killing the main body of the spore will also kill the tentacles.
 * At this point the surviving Vithrack will no longer be hostile, and Terenat will thank you for saving his people (though he has nothing to give you). Return to Foreman Ismey to explain the situation and finish the quest.  She will ask you to decide Gamel's fate.

Characters

 * Terenat, a sane vithrack.

Enemies

 * Vithracks
 * Vithrack
 * Vithrack Brute
 * Vithrack Luminary
 * Animated Weapons (summoned by Vithrack Luminaries)
 * Spiders
 * Crystal Eater
 * Moon Spiderling
 * Moon Spider
 * Spores
 * Radiant Sporelings
 * Radiant Spore Tendrils
 * Radiant Spore
 * Dominated Kith

Notable loot

 * Silver Flash: In the Vithrack Common Room, on a table.
 * Elryn's Jacket: In the Brute Quarters, in a trapped container (difficulty 13).
 * Mind Grubs: A consumable found only here, throughout the Luminescent Caves. Seems Vithrack know how to deal with Mind Flayers.