Crimson Desert Forbidden Knowledge Walkthrough

Forbidden Knowledge is Chapter 4’s main story quest in Crimson Desert. It’s where Kliff follows Alustin’s trail into Hernand and accesses Scholastone Institute under disguise. Along the way, he gets pulled into Octavius’s Abyss experiment and ends up fighting the Tenebrum boss before climbing the Spire of the Stars. Here, he finds a deeper Abyss connection that sends him back to Howling Hill and closes Chapter 4.

The Forbidden Knowledge questline is split into seven subquests in Crimson Desert, which you’ll have to complete in order:

The Words of Alustin
Scholastone
On the Right Path
Gate to the Otherworld
Spire of the Stars
Obsession and Madness
Casted Shadow

How to Unlock All Abyss Gear Blueprints in Crimson Desert

Here’s the full list of all Abyss Gear Blueprints in Crimson Desert, where you can find them, and what they do.

The Words of Alustin Walkthrough

The Forbidden Knowledge quest begins in Hernand, where a random encounter with an unnamed messenger interrupts your movement through the city streets. Soon after, you’ll receive Alustin’s Letter, which is the key trigger for the entire chain.

If you don’t run into the unnamed messenger, simply move around the area and reload or reenter the zone to trigger it.

Once the letter is in your inventory, open it and read it to unlock your next destination. The instructions point you toward Scholastone, a restricted institute located far into the colder western region of Hernand, near Fort Perwin.

Scholastone Walkthrough

You can’t reach Scholastone without a disguise. As such, first head toward the fence contact arranged through Alustin and enter the building near the town square. Inside, you meet Darroch, who will give you the Scholastone Uniform. This outfit is required to bypass the magical barrier blocking the hidden cave entrance leading to the institute.

Next, travel west into the colder mountain region. Stamina recovery will become noticeably slower due to the freezing environment.

Eventually, you’ll reach a concealed cave blocked by an energy field. Equip the Scholastone Uniform to cross the barrier. You’ll learn the Focus Force Palm mechanic here, which lets you interact with glowing energy sources that open pathways further in.

After activating the mechanism, a Troll NPC guides you toward the institute. From here, you can either climb directly or follow the winding path leading up the mountain until Scholastone comes into view.

On the Right Path Walkthrough

Once you arrive at the Scholastone Institute, the next objective is to meet Dean Grundir. He appears on a bridge inside the complex after you pass through the main entrance. Wearing the uniform lets you blend in without suspicion, so you can follow him freely through the institute. He eventually introduces you to Octavius, who is important for the next phase of the Forbidden Knowledge quest.

After the introduction, you will have to wait approximately one in-game day before continuing. When the time passes, talk to Octavius to start the experiment.

Gate to the Otherworld Walkthrough

Before you can start Octavius’s experiment, you need to solve a puzzle beneath the Scholastone plaza. To reach the underground chamber, jump from the ledge where Octavius is standing by taking the nearby stairs, or simply drop off the ledge and glide down into the lower room.

Inside, you find a locked mechanism composed of multiple tiles that all have to be activated simultaneously. Each tile affects others when pressed, so the order matters. The correct sequence is:

Press the top left button
Activate the bottom right button.
Hit the top right button.
Press the bottom left button.
Press the central button to complete the sequence.

Once done correctly, every block will lock into place, the system will stabilize, and the dome will open.

With the puzzle solved, your next task is to power the device by inserting four energy cubes into the pillars above Octavius’s position. Use Axiom Force to pick up each cube and carefully position it in front of its corresponding slot. When aligned properly, switch to Force Palm to push it into the socket and secure it.

How to Insert the Batteries to Activate the Device in Crimson Desert

How to Insert the Batteries to Activate the Device in Crimson Desert (2)

How to Insert the Batteries to Activate the Device in Crimson Desert (3)

Completing all four triggers Octavius’s experiment, which immediately goes wrong. The unstable core becomes the main threat. Use Axiom Force to grab it from the center of the structure while avoiding interference from the collapsing system. This action triggers the Tenebrum boss fight.

Defeat Tenebrum

Tenebrum is a floating entity that cannot be defeated with normal attacks. The best strategy to defeat him is to use environmental updrafts to glide toward it and strike with Force Palm mid air. Each successful hit removes a large portion of its health, meaning only a few clean attacks are required. The boss frequently releases wind bursts and shadow projectiles, so use pillars as cover and time your glides properly.

After three solid hits, Tenebrum is defeated, and you get a Key to the Spire of the Stars.

How to Unlock All Abyss Gear Blueprints in Crimson Desert

Here’s the full list of all Abyss Gear Blueprints in Crimson Desert, where you can find them, and what they do.

Spire of the Stars Walkthrough

The next destination is the Spire of the Stars. It is located at the mountain peak above Scholastone. The path is icy and reduces stamina regen, so make sure you maintain warmth through gear or food buffs. A cloak with ice resistance from the institute shop can help.

Follow the staircase route through caves and snowy paths until you reach the entrance. At the door, insert the obtained core to unlock the spire.

Spire of the Stars Puzzle

To activate the Spire of the Stars, you first need to solve the entry puzzle inside the main chamber. Start by using Force Palm on the three side walls with yellow-lit panels, which flips them around and reveals hidden engraved stones needed for the mechanism.

Take these stones and place them into the empty symbol slots on the central wall, where one symbol is already fixed in place. Once all pieces are inserted, the symbols shift into position and the elevator structure activates, raising the platforms above each symbol.

Next, climb up and interact with the raised symbols by hanging onto them to gradually lower each one into its correct vertical slot. The puzzle is all about positioning. The correct alignment is:

Left symbol goes in the top slot.
Middle left symbol goes in the second slot from the top.
Right symbol goes in the second slot from the bottom.
Middle right symbol goes in the bottom slot.

If you overshoot a placement, you can reset a symbol using Force Palm at the base to shoot it back up and try again.

When arranged correctly, the elevator powers up and carries you to the upper level. From there, continue up the stairwell until you reach the Abyss Gate.

Obsession and Madness Walkthrough

Inside the Abyss, you begin on unstable floating platforms connected to large magnetic pillars. Each pillar can pull your platform across gaps when activated using Axiom Force. The correct approach is to move gradually from one pillar to the next, starting with the central structure.

As you move, you have to repeatedly switch between platforms and activate new pillars to continue forward. Eventually, you reach a climbable section that leads to a higher island.

At the top, a glowing pressure plate awaits. Activating it with Force Palm triggers a major cutscene introducing a mysterious figure and ends the Abyss sequence abruptly, returning you to Scholastone.

Casted Shadow Walkthrough

After exiting the Abyss, you regain control in Scholastone where Dean Grundir confronts you about the events that took place. Once the conversation ends, you are free to leave the institute.

The final objective is to return to Howling Hill and regroup with the Greymanes. Once you reach your camp and enter your tent, the Forbidden Knowledge questline concludes and Chapter 5 begins.