Tomb of the Unproved Overview - Baldur's Gate 2
The Tomb of the Unproved is the final dungeon you'll be tasked with completing for Hexxat's Companion Quest. In order to unlock this dungeon you will first have to complete the Crypts of Durkon dungeon then wait one week for Cabrina to approach you and your party. Much like with the Crypts of Durkon you will have to enter the Graveyard District of Athkatla to be teleported to this map.
On this map your main objective is going to be obtaining the Shroud of the Unproved from the chest behind Raffiyah. You'll find Raffiyah in the northeastern portion of this dungeon.
Spirits & Chest: Here you'll find a group of spirits that will give you some information about this dungeon if you talk with them. I'd recommend either pick pocketing them or attacking them for the items they carry and the EXP they give. There is also a chest here which contains some quest items that you can use throughout this dungeon but it's all optional and a waste of your time.
Trap Room: The items you loot from the chest at the previous location I pointed out are used in this room. If you have the Scimitar +1 then the warrior statues will come alive and attack you in this room; if you have the Golden Statue then it'll weigh 1000lbs when you try to cross the spikes on the ground. Last but not least if you have the Lamp of Oil it'll cause a Fireball to strike ontop of the brazier in this room which will destroy some statues and summon an angry djinni who will drop Rashad's Talon +2. The last thing to note about this room is if you use Stone to Flesh on the remaining statues you'll gain access to the chest in the middle of this room that contains Boots of Elvenkind.
Tale of the Prophet Unproved: You'll need to pick up this book in order to unlock the correct answers at the Quiz Face later in the dungeon. Without this book even if you know the correct answers you won't be able to proceed.
Floor Tile Room: In order to progress through this room you can't step on any cracked tiles or tiles with web on them. Stepping on any of those tiles will result in spiders being summoned and you being teleported back to the start of this room.
Quiz Face: At this stone face you'll have to left click on it to place your hand inside then answer all 4 of the questions successfully. For the final question you're asked it doesn't matter what answer you choose, all 3 will work. Below are the correct answers for progressing.
1. Rabi'ah, Aminah, Bilqis and Sukayna
5. Answer anything
Raffiyah: The final big bad enemy in this dungeon is named Raffiyah and you can take a peaceful approach with her or a hostile one. I'd recommend just attacking her because if you peacefully resolve this part you will get no EXP. When you loot the Shroud of the Unproved from the chest in the back you'll earn 22,000 EXP for each character in your party. If Raffiyah gives you the shroud you get nothing.