Baldur's Gate 3 - Necromancy Of Thay And Search The Cellar Guide (2025)

By Jason Rodriguez on September 5, 2023 at 3:47PM PDT

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There are many secrets in Baldur's Gate 3. Some also invite you to take a step down a perilous road by following in the footsteps of dark magicians of yore. Our guide discusses the Baldur's Gate 3 Necromancy of Thay, the book of the dead, and a key objective in the Search the Cellar quest.

How to Obtain and Unlock the Necromancy of Thay in Baldur's Gate 3

To unlock the Baldur's Gate 3 Necromancy of Thay, you must pick it up from the Whispering Depths, then bring it all the way to the Sorcerous Sundries. This is a lot easier said than done. That's because the Whispering Depths is a location in Act 1, whereas you only get to visit the Sorcerous Sundries during Act 3.

Search the Cellar - How to Get the Necromancy of Thay

Our first task is to start the Baldur's Gate 3 Search the Cellar quest. Here's a quick summary:

• Enter the house to the left of the Blighted Village's entrance (X:37; Y: 379).
• Read the Apothecary's Ledger on the counter to get the quest.
• Climb down to the cellar via the wooden hatch that's nearby.
• Down below, read the Healer's Log to learn of balsam ointment. This is an answer to a question presented to you in the next part.
• Next, check the lever behind the crates. Interact with it to reveal a hidden passageway.
• You can then sneak past the coffins in the chamber to avoid battling some hostiles. Your goal is to reach the Ornate Mirror off to the side of the tunnel.

The Ornate Mirror

The Baldur's Gate 3 Ornate Mirror will ask several questions, and you need to convince it of your intentions. Here's what we chose:

• State your name.
• "Yes, an ally! An ally of your master's."
• When discussing Szass Tam: "A foul lich. May he die a thousand more deaths."
• When asked about balsam: "I read a doctor's journal. He used balsam to clean a wound."

The Dark Magician's Lair

The Ornate Mirror will let you pass, and this will allow you to proceed further with the Baldur's Gate 3 Search the Cellar objective. You'll now find yourself in a dark magician's lair. Here's what you need to do:

• Head to the right to pick up a rusted key. The lever here also causes the wall to move, which brings you back to the cellar entrance.
• Go to the left-hand side of the lair. You'll notice a trap on the floor that can be disarmed.
• Use the rusted key to unlock the door.
• Before picking up the tome on the altar, you can also disarm the two gargoyle traps. It's a bit iffy, because they would sometimes trigger forced turn-based mode.

In any case, you should now be able to pick up the Baldur's Gate 3 Necromancy of Thay. Ideally, you'll want either your main character or Gale to interact with it:

• Gale fits a more lore-friendly approach. After all, he's a Wizard with the Sage background, and he loves learning new things.
• Your main character, hopefully, has decent Wisdom stats, due to several dialogue checks later.

Whispering Depths - The Dark Amethyst and the Phase Spider Matriarch

You won't be able to open the Baldur's Gate 3 Necromancy of Thay just yet. That's because you need to find the Dark Amethyst.

The Dark Amethyst is in the Whispering Depths, the caverns underneath the Blighted Village. You can either go down via the well in the center of the village, or you can go through the cellar in the blacksmith's forge where you tackled the Finish the Masterwork Weapon side quest. Here are the next steps:

• Make sure everyone is hiding when moving around, since you'll deal with several Phase Spiders. They have poisonous attacks, and they can teleport.
• You'll want to reach the northwestern portion of the caverns (X:-565; Y:-355). However, it's also guarded by a Phase Spider Matriarch, with a whopping 125 HP.
• The best way to defeat the Phase Spider Matriarch is by ungrouping your squad, and having someone with Thunderwave (or a similar variant) sneak up behind the creature. This lets you push the spider queen down to the chasms below.
• Taking out the Phase Spider Matriarch quickly also nets you the "Pest Control" achievement, since you were able to kill it before the eggs hatched.

How to Begin Reading the Necromancy of Thay

When all the enemies are dead, pick up the Dark Amethyst. You can now use it to open the Necromancy of Thay.

Be ready for three instances where you need to pass Wisdom saving throws: DC10, DC15, and DC20. Use every buff you have to succeed, since failure may cause the book to remain shut for good. You can also keep a backup save, if need be. Alternatively, you can read the other pages later once you've acquired feats or items that increase your Wisdom stat.

Sorcerous Sundries Vault

The Sorcerous Sundries area is part of Gale's companion quest, and you only get to visit it during Act 3. You can learn more about all the tasks in our Sorcerous Sundries Vault guide. Here's a quick summary:

• In the vaults, pass through the Silverhand door.
• Then, pass through the Evocation door to reach the next chamber.
• Choose the Wish door and interact with the lever.
• Choose the Foresight door to return to the main area.

This will let you enter Elminster's room, which has the Tharchiate Codex inside a display case. Open it and read the book (be sure to use Remove Curse to cleanse the debuff).

Your main character or Gale (whoever read the Necromancy of Thay earlier) should now be able to decipher the runic symbols. This unlocks the Danse Macabre spell, which allows you to summon ghoulish minions in battle.

And that's everything you need to know about the Baldur's Gate 3 Necromancy of Thay and Search the Cellar objective. It's been a long journey, but you've finally learned its secrets.

Baldur's Gate 3 is filled to the brim with activities and secrets. You'll no doubt be part of an adventure that can take countless hours to complete. For other tips, you can visit our BG3 guides hub.

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