After your fight with Ketheric Thorm at the top of the Moonrise Towers, you eventually wound him, and he escapes.
This causes you to follow him deep into the Morgue by jumping after him where several discoveries are made in the Necrotic Laboratory.
One of the discoveries you will make is an alien-like contraption that has a puzzle for you to solve, which opens up a Flesh-Wrought Door near it.
Where To Find Necrotic Laboratory Puzzle?
The Necrotic Lab Puzzle location can be found by proceeding to the southwest of the Morgue which is where you will encounter Chop and the Intellect Devourers.
You will need to be able to reach this through 2 doorways but will have to deal with a group of enemies that includes a Death Shepherd, Winged Horrors, Greater Zombies, and Zombies.
Once you clear the room with the enemies in it, proceed to make your way to the southwest part of the Necrotic Laboratory and you will find the puzzle there.
Necrotic Laboratory Puzzle Solution
The puzzle in the Necrotic Labs can be solved by connecting the Main Nodes to the end of the paths leading to the proper ones at the end.
There are 4 paths that need to be completed, which are:
- Speech (Blue)
- Reason (Purple)
- Memory (Green)
- Emotion (Yellow)
Selecting a Main Node will allow you to start its path, which you may do by selecting the nodes that it is connected to until you eventually reach the end.
You can reset your progress at any time if you need to redo the puzzle if you happen to make a mistake while solving it.
The key to solving this is making sure that each of the Main Nodes reaches their partner nodes at the end, which unlocks the door.
A good way to do this would be to select each Main Node and proceed to a neutral node once, repeating this with each Main Node so you can carefully progress.
Another way and probably faster for some would be to focus on a single Main Node first and complete it before moving to the next.
Puzzle Rewards
Once the puzzle has been solved, the Flesh-Wrought Door will open, and you will find a Waking Mind and the Blade of the Oppressed Souls.
A skeleton will be nearby as well and opening its inventory will allow you to take the following items:
- Bone
- Circlet of Mental Anguish
- Braindrain Gloves
The Waking Mind that you find can be used at the nearby Mind-Archive Interface which will allow you to Githzerai Mind Barrier condition.
Verdict
The Necrotic Lab Puzzle offers you the chance to get certain items that can be useful for your build, especially when it comes to the Braindrain Gloves and the Blade of the Oppressed Souls.
The Githzerai Mind Barrier condition provides you with an advantage against Intelligence Saving Throws and there is no trouble at all to get once you solve the puzzle.
Solving the puzzle may take a few tries as sometimes paths can accidentally be blocked, making it necessary to plan before selecting each node.