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Baldur's Gate 3

Baldur's Gate 3 - Necromancy of Thay Walkthrough: Key and Powers

Craig Robinson

For those who worked their way through the Search The Cellar quest in the "Blighted Village" iconBlighted Village, you will have found a fancy legendary book, belonging to the Thay Liches and Necromancers. However, the book holds a lot of mystery; with it, you get a quest, with no real explanation as to what you need to do. However, we are here to help you find the Necromancy Of Thay Key, so you can begin to explore the book and learn of its dark and deathly secrets.

Here is how to complete the Baldur’s Gate 3 Necromancy of Thay questline.

Necromancy Of Thay Key location in Baldur’s Gate 3.

You can climb down this well in the Blighted Village if you wish to find the Necromancy of Thay Key.

To find the "Necromancy of Thay" iconNecromancy of Thay key, you must explore the "Whispering Depths" iconWhispering Depths. The Blighted Village is built on top of a series of cave systems you can find in a few ways.

  1. One is via the Well in the Blighted Village
  2. The other is through a cellar door in one of the houses in the Blighted Village.

Pick which one you want to venture through, and you can enter the Withering Dark. The best one is the likely the well, as it gets you closer to the Necromancy Of Thay key deeper in the cave system.

Once you’re inside the Withering Dark, you now need to do the following:

  1. Travel West from the Water Bucket and continue through the Wither Dark.
  2. You will encounter some Phase Spiders. They’ll be slightly tough, but you can short res or long rest ahead of the boss battle.
  3. Eventually, you’ll come across an area with many webbing bridges between several elevated positions. This is a boss fight room. We recommend Long Resting here so you can be prepared for the big battle to come.
  4. Around the boss fight room, you’ll notice a "Dark Amethyst" iconDark Amethyst. This is the Necromancy of Thay key you must use when reading the book.

Fighting the Phase Spider Matriarch

Here are the locations of the Necromancy of Thay Key and the boss that guards it.

The boss battle in question is the Matriarch of the Phase Spiders. She will do variations of leap attacks and poison bites when you fight her. She will also call Phase Spider Hatchlings to her location. There could also be some Phase Spiders that get brought in to fight you too. So, we recommend you do some sabotage missions first. If you can take care of the nearby Phase Spiders, and maybe stealth kill some of the Spider Eggs around the room, you may have a better shot at this.

When you’re in combat, and the boss calls her Spiderlings to assist, they will likely swarm a character if they travel along a path near where an ally is positioned. Most often this is a ranged character. If you have someone in your party who can summons a creature, you can have them tank it, such as a Beast Master Ranger or Warlock Familiar. Alternatively, you can have a character with an AOE spell, or a weapon ability like "Cleave" iconCleave, as that will make eliminating several targets much easier. Alternatively, you can throw some form of grenade at them from your inventory if you so wish. They have around 7 HP, so they should fry off no matter what method you use to handle the situation. Other times the spiders will likely jump to the odd character here or there. These can be ignored, as they won’t really do much damage. But, if you do handle them, you likely waste an action on them to kill them. Thief Rogues, however, are fine, as they will more than likely beat them with the double bonus action attacks.

The other thing to be mindful of is the webbing bridges. You’re pretty much constantly rolling a saving throw against getting webbed. It’s something worth watching for if the boss paths to a web, as your ranged character will be better focused on the Matriarch. The jump action is great if you need to have melee characters jump into the boss’ melee range. It will make traversing the fight easier for melee characters, and reduce the risk of being webbed up.

Necromancy of Thay Walkthrough Continued

(1 of 2) Be prepared to use buffs from your support classes like Paladin, Cleric, Druid and Bard to make the literacy session go in your favor.

Be prepared to use buffs from your support classes like Paladin, Cleric, Druid and Bard to make the literacy session go in your favor. (left), Don’t be afraid to use some spare inspiration if you don’t fail the very difficult 20 roll. (right)

Now that the fight is over, you pick up the Dark Amethyst key for the Necromancy of Thay. Now that it is in the inventory of the same person you plan on using the book with, you can go ahead and read it. You will now find a new option to open the book using the gem.

You will get a series of Wisdom saving throw checks to read the book when you open it. The first check requires a ten, the second 15, and the final one a 20. We highly recommend using the book on someone with a decent Wisdom score and who does not already have the power to Speak to the Dead. These options are typically Clerics, Druids and Rangers. If you manage to read all three pages, you will unlock that spell for the character who reads it.

In addition, you can also get access to some good buffs here. You can get a few bonuses when you start the rolls to open the book and read the three pages. Things like "Bless" iconBless from Paladins and Clerics work great, while the "Resistance" iconResistance Cantrip also works, which you can find from Clerics and the Circle of the Land Druids, among other classes. "Shadowheart" iconShadowheart has access to both of these, making her a very good companion to use here. You can also use something like Owl’s Wisdom, which Clerics, Bards, Wizards and Sorcs can use.

Now you’ve decided on the bonuses to use and who will read the book, it’s time to read. Make those three rolls, and you will have the book close itself on you. If you were successful, you unlock that character’s Speak to the Dead spell. It is unclear if you get the chance to open this book again in the full release of the game. Perhaps it could have interactions with the Necromancer subclass for Wizard, and it could become active again as the game progresses for more undead powers to appear.

Necromancy of Thay in Act 3

Once you’re in the room, break the case, and then grab yourself the book related to the Necromancy of Thay.

For those who make it to Act 3 with the book still intact, then there’s another piece to this puzzle. As you get to a place called !Sorcerer’s Sundries, you can find special Sorcerer Vaults inside, filled with traps and puzzles to solve. If you manage to complete the main puzzle for Elminster, then you will find a Codex inside the room. If you read it, you will then be able to open the final page of the Necromancy of Thay. Pass the check, and if you do, you will get some special powers to control multiple undead creatures at once.

If you visit the Temple of Shar in Act 3, there is a feature called the Mirror of Loss. The Mirror of Loss can give you +2 to a chosen ability score if you manage to sacrifice something in return and pass some checks. One of the things you can sacrifice is the powers learned from the book. So, you can lose access to the Speak to Dead and the ghouls feature. We don’t recommend doing this, but its there if you want it to.

Destroy the Necromancy of Thay

Dealing two radiant damage to this book will destroy its unholy aura.

The final option in this entire ordeal is to not bother with the book and destroy it instead. The book is immune to all damage, except for Radiant damage. The only characters that use Radiant Damage are Clerics and Paladins. From level 1, Clerics can access "Sacred Flame" iconSacred Flame and "Guiding Bolt" iconGuiding Bolt, which deal Radiant damage. Paladins may also use Divine Favor and get a 1d4 radiant damage roll on attacks. Using any of these options is good enough to destroy the book.
If you do so, the entire quest end here.

With that said you now know how to complete the Necromancy of Thay quest in Baldur’s Gate 3.

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Guide Information
  • Publisher
    Larian Studios
  • Platforms,
    Mac, PC, PS5, XB X|S
  • Genre
    Adventure, RPG
  • Guide Release
    6 April 2023
  • Last Updated
    14 June 2024
    Version History
  • Guide Author

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Baldur’s Gate 3 is an immersive roleplaying game set in the Dungeons & Dragons universe. It features a rich story with multiple outcomes for almost every encounter, and plenty of character customization features including more races, classes, subclasses and party combinations than you are ever likely to explore. The seemingly endless possibilities and numerous choices that you can make throughout your journey make a helping hand always welcome, and that’s where we come in! This guide features the following:

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