Unlock the Ancient Tome is a sub-quest of Search the Cellar in Act One of Baldur's Gate 3. It is initiated upon finding the book "The Necromancy of Thay" in the Blighted Village.
 | Spoiler warning: The following content contains unhidden spoilers. Read at your own risk. |
Objectives
Objectives and journal entries may vary pending player decisions and outcomes.
- This book is locked tight, and the mechanism isn't shaped for a key. Maybe some kind of stone would work?
- The owner of the tome mentioned a keygem. Could this be the secret to unlocking 'The Necromancy of Thay'?
- The necromancer's apprentice mentioned a keygem lost in the tunnels. We need to find it.
- We found the gem to unlock the book.
- We've unlocked the book of necromancy. Should we read it?
- The tome is clearly powerful, but we'll need to read further to uncover all of its secrets.
- We managed to read most of the book, absorbing some of it's necromatic power, but it snapped shut before we could finish. There must be a way to read the end.
- We made it to the final page of the tome, but it's indecipherable. We need to find a way to read it.
- Mystic Carrion and his Spirits told us that we need the 'Tharchiate Codex' to unlock the true power of 'The Necromancy of Thay'.
- Mystic Carrion and his Spirits told us that we need the 'Tharchiate Codex' to unlock the true power of 'The Necromancy of Thay'.
- We've accessed the vault, and the lower level of Sorcerous Sundries. Now to find the 'Tharchiate Codex'.
- We have the 'Tharchiate Codex'. To decipher "The Necromancy of Thay', we need to first read the codex.
- We read the 'Tharchiate Codex', and now have the knowledge to finish 'The Necromancy of Thay'
Walkthrough
Unlocking the Book
The Necromancy of Thay is obtained during Search the Cellar within the apothecary's secret laboratory past the ornate mirror. Removing the book from its trapped room starts a quest to either unlock the Necromancy of Thay's secrets or destroy it forever. Retrieving the tome from the apothecary's cellar is only one part of unlocking it - it also requires a key to open.
There are two ways to find the Dark Amethyst needed to unlock the book. One way is to enter the blacksmith's basement north of the Blighted Village waypoint (this is also the same basement where Finish the Masterwork Weapon is completed). One of the northern walls is cracked and can be destroyed with force damage, which leads to the Whispering Depths. The other way is to investigate the well (X:23, Y:400) north of the waypoint. Choose "[INVESTIGATION] Peer into the well" and then climb the bucket rope ladder down into the well to arrive at the cave. Inside the cave is an Apprentice's Pack (X:-494, Y:-364) which has more information on the stone's whereabouts. It's deeper within the cave. The Dark Amethyst is in the western area of the cave (X:-563, Y:-353) below a Spider Matriarch's webs. Either sneak past the horde or spiders, or defeat them all. Defeating the matriarch grants Poisoner's Robes.
Reading the Book
With both the Dark Amethys and the Necromancy of Thay in the party's inventory, click on the Necromancy of Thay. This starts a dialogue with the party inspecting the tome. Select ""Place the amethyst in the slot on the book's cover" to unlock it.
From here, there are several options:
- Open the book
- Give the book to Astarion
- Drop the book and proceed with Destroy the Ancient Tome
If the book is opened, it requires three Wisdom checks. The first is DC 10, the second is DC 15, and the third is DC 20. Passing the first check grants the Speak with Dead skill and passing two of the checks grants a buff, Forbidden Knowledge, which grants a +1 to Wisdom saving throws. Failing results in the Whisps of Madness and Baleful Knowledge debuffs. Once all three checks are complete, the book snaps shut. The book has more secrets to unlock.
Choosing to give the book to Astarion results in approval points from him and a special cutscene at camp.
Unlocking the Book's Secrets
More hints about the Necromancy of Thay can be found within the Silent Library within the Gauntlet of Shar. One of the books refers to a Tharchiate Codex that can unlock the tome's true power. Additionally, speaking with Mystic Carrion in the Lower City of Baldur's Gate reveals that Sorcerous Sundries holds the Codex in its lower vaults.
The Tharchiate Codex can be found in the Elminister Section of the Sorcerous Sundries' vault. Interact with the book again and the spell Danse Macabre is granted.
If the book was given to Astarion, then he must be the controlled character and have the Tharciate Codex to fully understand it.
Rewards
Notes
- Gale can technically consume the Necromancy of Thay book, which destroys it without granting any of the abilities or knowledge. He can also read it like normal, if the item is sent to his inventory and he reads it while being the controlled character.