How to complete Gate to the Other World in Crimson Desert

Crimson Desert Gate to the Other World - Octavius.

You'll find yourself helping with Octavius's experiment in Crimson Desert shortly after you arrive at Scholastone. This giant scholar is trying to open a portal to the abyss, and the head of the academy will enlist your help in setting up the apparatus. Similar to repairing the kilns for Grimnir earlier in Chapter 4, the Gate to the Other World quest is almost-entirely puzzle-based.

I'll run through each stage of the puzzle below, plus explain how to complete the fight at the end of it so you can continue your journey.

Activate the lock device switch underground

The lock puzzle downstairs requires you to light up all nice tiles by pressing them (Image credit: Pearl Abyss)

For this first step you'll have to head to the floor below, so drop down via the edge of the courtyard and glide into the floor underneath. Navigate to the lock device and interact to start the puzzle—you need to press the nine tiles in such a way that they all light up. While there are probably multiple solutions, press the tiles in this order:

1. Middle tile of the middle row
2. Top left
3. Bottom right
4. Top right
5. Bottom left

Now interact with the switch to start things running.

Insert the batteries to activate the device

Use Axiom Force to place the batteries then Force Palm them into each slot (Image credit: Pearl Abyss)

Now you have to head back the courtyard above via the staircase off to the left side of the open pillared section. Once back up above, use Axiom Force to move each sparking blue battery into position in front of its slot, then hit it with Force Palm to smack it into the slot. After all four are in-place, Octavius will begin his experiment.

How to defeat Tenebrum

Use Axiom Force to pull out the core then defeat Tenebrum by flying close and using Force Palm when it stays still (Image credit: Pearl Abyss)

Unfortunately, things don't go well. Shortly after it opens, the portal becomes unstable, and you'll have to "Use Axiom Force to remove the unstable core", which you do by grabbing the glowing ball at the centre, holding the control button, then pulling it to one side to tear it away.

Octavius will get sucked up by his experiment and it'll summon a hostile ball of energy called Tenebrum, which you'll have to defeat. After a short tutorial teaching you how to use Blinding Flash to highlight enemy weaknesses the fight will commence. Defeating Tenebrum is relatively easy:

1. Hop into the air and fly while targeting it, avoiding the black tendril attacks
2. Wait for it to move to the centre of the arena and charge a shockwave
3. Use Force Palm midair while it's doing this to take off a chunk of its health

Rinse and repeat three times and you'll defeat the boss, concluding Octavius's unfortunate experiment.