Once you’ve fought your way through a literal army of the undead, you’ll find at the end of the library a control panel and a unique puzzle that will require you to select the right path. This is the necrotic laboratory puzzle, and here’s how to solve it in Baldur’s Gate 3.
Baldur’s Gate 3: Necrotic Lab Puzzle Solution (BG3)
Some wicked things are happening in the Necrotic Lab. And that might be best demonstrated by the Necrotic Laboratory puzzle, where a mind’s been fragmented. But if you select the right path, you can stitch things back together and, more importantly, open a door.
Here’s how it works.
There are three nodes that you’ll have to guide from the control panel to the end. These nodes are Memory (green), Reason (purple), Speech (blue), and Emotion (yellow).
The way this puzzle is solved is actually very straightforward. Each of these starting nodes has a specific shape, which matches a shape at the end of a white line. You’ll need to identify the white line that connects the two nodes together.
To start a node’s line, click it first. It will glow, letting you know it’s active. Then you can start selecting the points along its white line. To avoid clicking on the wrong point, move your camera around the shape.
Related: Baldur’s Gate 3: How to Use the Iron Flask (BG3)

Here’s the completed puzzle, as seen from its left side.

Here’s the completed puzzle, as seen from its right side.
Once you’ve correctly connected all four nodes together, the control panel will greet you, and the door will open. Your prize will be the rare sword Blade of Oppressed Souls and the Waking Mind, which is associated with a quest in the Necrotic Lab that is currently bugged.
Blade of Oppressed Souls | Weapon Enchantment +1. 1d10 (1d8)+5. +2 Acid. +1d4 Psychic. |
While you’re here in the pink, fleshy depths, you can find Wyll’s patrol, Mizora. While Mizora usually has the upper hand, you’ll have a chance to end her once and for all. But should you?