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Several artifacts lay scattered acrossBaldur’s Gate 3, but few are so close to your starting position than the Ancient Tome, also known as the Necromancy of Thay. Available as soon as your first real town encounter, the book is kept well-hidden right under your nose. You’ll need to keep a vigilant eye and scour every corner to find its location and unlock its secrets.
Of course, getting the book won’t be enough; it never is. Once the book has been found, you’ll also need to find a way to open it. And once you find the key, reading what lies inside is no minor challenge either. When it comes to the Necromancy of Thay, it’ll be one thing after the next.
Updated July 11, 2025 by Alexis Campbell:Included new information gathered from Act Three, finishing the Necromancy of Thay informal questline and trading secrets of the book with the Mirror of Loss in lieu of unwanted Ability Score Points.
How To Find The Necromancy Of Thay
Past The Mirror Of Riddles
Resting in a secret laboratory beneath theBlighted Village, you’ll first need to scout out the secret entrance to anapothecary’s basement.
From the main gate (where the goblins on the roof speak with you on the side facing the beach and the druid’s grove), enter thefirst house on the left.
In theroom with the double doorsto the outside and closest to the Waypoint, you should find ahatch on the floorleading to the basement. It’s behind the counter. Open it todescend into the basement.
The basement contains several helpful herbs, potions, and a few small trinkets of worth. Of the seemingly insignificant items, the one you’ll want to pay attention to is abook sitting on a table on the left side of the roomcalled the"Healer’s Log.“Inside is information that will be the key to answering a riddle later.
After reading (and maybe taking) the book,walk toward the large wooden cabinetwhere your characters may roll a passive perception to notice scratch marks on the ground.
To move the cabinet,pick up and move or destroy the three boxes stacked to the left.A hidden lever behind it can be found there.
Pull the lever,and thengo through the newly opened doorto the right of the cabinet.
A yard of dug-up caskets can be found on the other side, and snooping through them will cause several undead skeletons to rise from their coffins. Unless you’re looking for the fight,ignore the coffins and instead approach the mirror.
The mirror will ask you a set of questions, and you mustanswer them all as such to proceed:
Failing to answer the mirror correctly will trigger a fiery orb to appear from the mirror and attack you while waking all the skeletons hiding in their caskets nearby.
Alternatively, if you roll high enough, youcan Intimidate the mirrorinto letting you pass. If you fail or answer the questions wrong, however, it will summon an orb that sprays fire at you.
Entering the laboratory, you’re able to find several powerful potions and spell scrolls. Loot what interests you andignore the iron doorbetween the braziers for now.
Head toward the exit,where a lever can be pulled to open the way back to the Apothecary’s Basement section. After the shortcut is open, turn to the side andinspect the nearby shelves for aRusted Key.Take it.
You can skip finding the Rusted Key and the entire section below if you carry and cast the spellMage Hand. Use it to reach through the iron door and pull the book through the metal bars without fearing any traps.
Approaching the iron dooronce you’re ready, you maydiscover a trap on the ground in front of the door.Stepping on it only seems to activate the braziers, so you can choose to Disarm it or not.
Open the doorwith the Rusted Key and discover the Necromancy of Thay inside.Don’t pick it up.Instead, there is atrap beneath the bookand a trap in each of thegargoyle statues on either side of the room. Disarm them all.
Alternatively, you cancast Mage Handinside the room with the book andthrow the book through the bars,bypassing all of the traps without having to make a roll.
Once the traps are disarmed, you’re able to finallypick up the booksafely. You may receive interest from either Astarion or Gale about taking the book. At this point, you havethree options:
How To Find The Dark Amethyst, AKA The Amethyst Key
Defeat The Phase Spider Matriarch
To find the Amethyst Stone, you’ll have to venture into the Whispering Depths. There aretwo paths into the Whispering Depthsin the Blighted Village:
The Whispering Depths is recommended only for party levels of at least three or higher.
Once inside the Whispering Depths, you’ll need toventure further to the bowels of the Depths.This requiresdefeating at least one horde of spidersand encountering themini-boss at the end:the Phase Spider Matriarch.
She’s, thankfully, a very straightforward fight so long as youstay on solid groundandlure her and her spiderlings to you.
Yes, her health is on the tanky side at 125HP, but her AC is manageable, and her bite attacks are not too devastating for a properly leveled party.
Your only concern for this fight is toavoid being poisonedby her bites and Venomous Discharge. Ensure youhave someone withHealing Wordpreparedto counteract the effects of poison while in combat.
UsingSpirit GuardiansorFireballwill be extremely useful here for their ability to one-shot kill the small spider minions. Guardians of Faith is the better option, as worrying about your team’s positioning is not necessary.
After defeating the Matriarch, you canclimb down a vine wall left of the spider web leading to a broken pillar(north of the entrance you came from) and where the Phase Spider Matriarch likely teleported to.
Down here is aPoisoner’s Robe, but the real prize lieson the other side of the large holein the center of the room.
Aglowing purple stoneon the other side is the Dark Amethyst.Pick it up and take it back to a safe place(like camp).
What To Do With The Necromancy Of Thay In Act One
A Difficult Choice That You Can Put Off Until Later
Once you’ve secured the Dark Amethyst, you may nowopen the Necromancy of Thay.
In a safe location, select the Necromancy of Thay in your inventory and Read it. This will prompt a dialogue where you may choose what to do.Insert the Amethyst Stone.
When the book opens, you’ll be givena few more options:
Giving the book to Astarionincreases his Approval and opens unique dialogues but ends the quest, leaving you unable to retrieve the book for yourself (or read it again later).
Opening the bookwill prevent you from receiving the option to give the book to Gale. However, you will automaticallygain an at-will special casting of “Speak with Dead"regardless of how you roll the saves required to peruse the book.
If you choose to open the book,you’ll need tomake three difficult Wisdom saves.First, a 10DC, then a 15DC, and finally a 20DC (or a 10DC to close it).
Failing one save will give you 50 turns of"Whisps of Madness”- a debuff that gives you Disadvantage on Wisdom ability checks. Failing two will give you a similar debuff called"Baleful Knowledge,“but it’s permanent.
If you suffer Baleful Knowledge, you can remove it with the spellRemove Curse. This is a third level spell learned by clerics, paladins, warlocks, and wizards.
Succeeding on the saves of the book will give you some unique insight into your future, but there areno known notable side-effects,either positive or negative.
Warlocks, Wizards, and Clerics of Shar and Lolth (especially Shadowheart) will have lower DCs and special options.
What To Do With The Necromancy Book Of Thay In Act Three
Ability Points Vs Spells
In the final act of the game, there aretwo things that can be donewith the Necromancy Book of Thay:
If you’vespoken with the Mummy Lord,the Mystic Carrion, in the Lower City, he’ll hint to you that the Tharchiate Codex is the keyto learning the real secret of the Book of Thay. If you want to follow up on this lead, you need tohead toSorcerous Sundries.
You canfollow this guideto locate the Tharchiate Codex in the restricted vault section.
After reading the Tharchiate Codex, you canopen the Book of Thay(if you did not give it to Astarion or Gale) and nowread the final section of the bookafter passing another saving throw (Wisdom DC 20). This will reward you witha Summon Ghouls spellyou can cast at will once per long rest.
This spellsummons six ghouls to your aid, a powerful boon to have in any situation.
Youmay prefer the other optionwith the Book of Thay if you:
Travel to theHouse of Griefand complete the questline there in whichever manner you see fit.
Once the house is cleared, you’ll gain access totheMirror of Loss.Passing its checks, the person who read the Book of Thay will have the ability toforget all their knowledge about the book in return for two points in an Ability Score of your choice.
Beware that this will cause you to lose any spells gained as a result of reading the book.
Baldur’s Gate 3
WHERE TO PLAY
Baldur’s Gate 3 is the long-awaited next chapter in the Dungeons & Dragons-based series of RPGs. Developed by Divinity creator Larian Studios, it puts you in the middle of a mind flayer invasion of Faerûn, over a century after the events of its predecessor.
