Illithid Hideout in the Sewers

Illithid Hideout in the Sewers is a dungeon accessible through a secret wall panel in the northeastern part (2484, 340) of the Sewers underneath the Temple District. The "fog of war" blocks any view of what might be beyond the panel, and no means of dispelling that obscured part of the map.
The secret wall panel can be discovered as early as Baldur's Gate II Chapter 2. The panel has a difficulty of 90 to detect. Examination of the panel will only reveal that it is "locked" with no other information. The panel can't be opened, nor will a Knock spell do anything, and it can't be forced. 
== Description of Area ==
Assuming the party was able to get the key needed to enter the corridor to this area, make way past the rotting corpses of unknown adventurers and climb the steps to the new map. The fact that some kind of force may have temporarily stunned the party weighs heavily on the mind.
Transitioning from the previous corridor in the Sewers, the party will see a strange and almost "alien" architecture, stonework, colorings, and perceive a foreign and unidentifiable background odor. The place is silent except for a barely discernable low frequency throb. The hairs on the back of your neck and arms seem to stand up on their own.
This place is not the work of elves, dwarves or human societies as far as one can tell.
== On the map ==
* No player "Automap" markers are available on this map.
== Gameplay (abbreviated walkthrough) ==
=== The entry chamber ===
The party makes the transition up the stairs into this round chamber. Everyone's senses take in the sights, sounds and smells. 
A soft illumination is provided throughout the room from the very material comprising the ceiling itself.
There are no denizens, objects, or furnishings to be seen. No debris or filth of any kind is observed. On the western side is a corridor leading further into the complex.
=== The second chamber ===
When ready, investigate the corridor leading westward, and a closed door of some kind of altered wood and iron is shut before you. Some barely audible sounds are picked up behind it - perhaps an unintelligible voice? It's too faint to make anything out, and the alien door is tightly fitted to frame and flush with the floor, although it has a conventional handle to open it with.
When prepared, open the door and peer inside or enter the next chamber - which is another roundish room, with a closed door on the western side.
Within are seen a group of somber humans in various dress. All are garbed in armor, or robes and they have weaponry readied. At the western side is a brutish Umber Hulk squatting down, and one of those horrible illithids, or Mind Flayer you've heard about (and maybe even faced before).
If any party members are detected, the group will spring into hostile action.
The archers will attempt to let loose arrows, the fighters will rush forward with their drawn weapons, the assassin will skulk and try and get in a piercing stab. There is also a cleric, and a mage in the rear that will try in earnest to get up some initial magic.
Keep an eye out for the charging umber hulk - which will likely precede that with its innate confusion attack. Likewise, the mind flayer will soon launch a Psionic Blast at the party.
If the party triumphs, various items can be gathered from the fallen humans, who were apparently dire charmed and controlled by the domineering illithids.
=== The third section ===
Steel your nerves and open another closed door leading westward. 
A fairly lengthy curving corridor stretches before the party, ending in another closed door. With all the noise created by the previous fight, it's unlikely that any other illithids within aren't already alerted to your presence. 
Use stealth or not and see what lies ahead. Within is a third circular room with fully alert brood of mind flayers and a pair of Ulitharid creatures. Another umber hulk pet is within as well.
When a party member is detected the illithids will launch their psionic attacks, then move toward the party to engage with their tentacles and attempt to perform a "Devour Brain" assault.
The umber hulk will also race forward and might be able to fire one of its confusion projectiles.
Plan your attack and defense as desired. You know that after these enemies there is yet another corridor leading to the north part of the complex.
=== The final chamber ===
Through a door a corridor curves north ending with a shut door. So far none of these doors has been barred or locked. As if the inhabitants don't worry about being invaded. The party will put them to the test and see if they can't clear out this nest of evil.
Make necessary preparations and enter through the door. Within is a room ringed by strange fonts of unusual liquid. A central one is also placed. 
Inside the chamber are two umber hulks, two ulitharids, three mind flayers and an Alhoon. When a party member enters the combat log displays a text message from this creature - it doesn't speak, so presumably this is some kind of telepathic message.
When a party member is detected, the group will initiate hostile actions and attack. Expect the usual onslaught of psionic attacks, confusion from the hulks, as well as some preparatory protective spells cast upon the Alhoon.
Note that the door to this room can't be closed once opened. It is likely that various monsters within will follow the party into the corridor. Perhaps this can be used to the player's advantage.
When the last of the illithid group falls, search the final room central container for some very nice loot. A cryptic manuscript is also found. 
Thus ends this strange gathering of evil below the streets of the temple district.
== Creatures ==
== Notable loot ==
* Hammer of Thunderbolts
* Wand of Wonder
* Illithid Correspondence
==Gallery Screenshots==
OG MF Sewer Secret.png|A secret wall panel is detected after the party dispatched the The Hatchetman's Party. The door is locked and can't be lockpicked or forced open.
Sewer MF 1.png|The party had the required key to open the secret wall panel - PC entered the new area past various dead adventurers and was jolted by a Stun blast.
OG MF Sewer 4.png|The illithids are aggressively following retreating party members. A hail of missile fire slows their advance in the chokepoint.
== Bugs ==
As of BG2EE 2.6, several doors in various areas, including this one, would disappear when opened, leaving no way to close them. This is identified for correction in the pending Enhanced Edition Fix Pack (EEFP).
Reference: (ar0406.are, ar0711.are, ar1302.are, ar1307.are, ar1307.are, ar5007.are)
== Spoiler ==
For further information regarding how to find the key to open the secret wall panel that allows entry to this area, a "Spoiler" reveal button is provided below. Don't open it if you want to figure this out on your own as the game intended for a first-time player. That's part of the game's immersion and appeal.
Defeat Tazok in Firkraag's Maze - the key is amongst his carried items.
== Mod content ==
The Golem Construction for Spellcasters mod places a bodyguard Brain Golem next to the Alhoon.
The Sword Coast Stratagems mod revises all the AI scripts for the enemies in this area. If the "Smarter Mind Flayers" component is installed this will greatly increase the variety of Psionic Ability choices available to the illithids, and help to counter some of the tactics used by players such as relying on Chaotic Commands. The illithids now have other ways to attack the party that can't be blocked with only one spell.
All illithids are typically invisible or under weak invisibility at the outset of battle with this mod. It makes single target spell casting difficult. 
A skeleton servant is also with the enslaved Cleric. The Assassin is now an actual assassin and will use Poison Weapon and backstab from invisibility, then try it again, and then yet again using potions to attain stealth.
And finally, the Alhoon is designed as a pseudo-lich/ulitharid, and has a wide array of arcane spells and HLA's.
These changes make this area probably too tough for a party to handle if still in chapter 2, but it depends on the player's skill of course.
==Mod gallery screenshots==
Sewer MF 4.png|Stealthy party scout enters the 2nd chamber - they know their door opened and now both spell casters are about to try divination magic.
Sewer MF SCS 1.png|The whole party boldly advances into the room full of dire charmed humanoids. Combat log of enemy actions and dialogue quips shown.
Sewer MF 5.png|Not eager to face such a prepared group, the party waits for them to advance to the entrance room. A mind flayer planar travels to us and a dominated human enters.
Sewer MF 6.png|SCS illithids see right through scouts' stealth in the second room. Ballistic Attack and Psionic Blast incoming.
Sewers MF Seven Eyes.png|PC "tanks" the 2nd room - fully buffed. Some rear party members still take Detonate damage.
Sewer MF 7.png|Party rogue is in a bit of trouble and is getting swarmed by illithids who can see through invisibility. Time to retreat before it's too late.
Sewer MF 8.png|Scout makes a quick visit to the final room. Some of the illithids are completely invisible - others are partially under weak invisibility. What's that? A Brain Golem?
Category:Dungeons