How to open the Necromancy of Thay in Baldur's Gate 3
The Necromancy of Thay key is an item you've got to hunt down in Baldur's Gate 3 if you want to open the mysterious dark magic tome you find in the apothecary's cellar in the Blighted Village. To get to the book itself, you've got to jump through all sorts of hoops, like opening a secret cellar door, tricking a magical talking mirror, and disabling some traps around the book itself.
You've also got to open the barred door in front of the book—you can grab the Rusted Key to do this from a shelf in the laboratory's westernmost room. This is right by the lever that lowers the wall, letting you back into the previous area, so it's hard to miss. Even when you have the book, you still have to unlock it, and ultimately decide whether you want to destroy it or take its power. Here's where to find the Necromancy of Thay key, plus what choices you can make.
How to open the Necromancy of Thay
Upon examining the Necromancy of Thay, you'll realise that you need another item to unseal the nightmarish book. This item is the Dark Amethyst, which you can find in the Phase Spider nest in the Whispering Depths, underneath the Blighted Village. Here's how to get it:
- Examine the well in the centre of the Blighted Village and either use Investigation or throw in a coin, before climbing down into the nest.
- While you can fight through the nest, Phase Spiders are tough opponents, so your best bet is to hide and sneak or even use invisibility if you have it.
- From the bottom of the well, head northwest until you find a skeleton and an Ettercap patrolling on a higher platform. Once its back is turned, sneak past it into the main nest with the Phase Spider Matriarch and a giant hole.
- You'll spot the Dark Amethyst on the far edge of the hole. Here, I use a scroll of Feather Fall, wait for the spiders to look away, then jump down, grab it, and then sneak away. Even if the spiders spot you, it isn't too hard to disappear again depending on where they warp to.
Necromancy of Thay choices
Once you've got the Dark Amethyst, you can open the book at any time by examining it in your inventory. Ultimately, you have three choices surrounding the book:
- Read it yourself: To learn the Necromancy of Thay's secrets, you'll have to pass three Wisdom skill checks of escalating difficulty—10, 15, and 20—as you turn each page in the book. If you succeed at all three you'll get the Forbidden Knowledge trait, which gives you a permanent +1 to all Wisdom saving throws and ability checks, plus the Speak with Dead ability. Reading the book will also inspire Gale.
- Give it to Astarion: Once opened, you can give the book to Asterion. He'll approve of this and look through the book briefly before holding onto it. Considering this a tome of Necromancy, it presumably tells him something important, but there are no immediate consequences.
- Destroy it: If you drop the book and use Shadowheart's Guiding Bolt spell, you can destroy the Necromancy of Thay, though I wouldn't advise this. Doing so will cause three very tough Shadow enemies to spawn and without a strong party, you'll die pretty quick. These Shadows are highly resistant to physical attacks and fighting them is just generally a bad time. The only real plus side to this is that you don't need to get the Dark Amethyst to do it.
- Hold onto it: There's no rush to open the book once you have the key, so you could always hold onto it until you are strong enough to beat the three Shadows, or if you suspect using the book might have unexpected ramifications further down the line.