Death’s Door is one of the main quests you’ll find in Horizon Forbidden West.
Your objective is to look for the trail left behind by Sylens and recover the GAIA backup.
Here’s a walkthrough of Death’s Door in Horizon Forbidden West.
The recommended level is 10 and above.
Go to the coordinates
The quest begins after you’ve reached the Forbidden West. Head to the location marked on the map below.
When you reach the area, you’ll see a dead titan. Head towards it, under the titan.
You will then see a console you can activate. Sylens will then appear in holographic form again.
Investigate Sylens’ workshop
Use focus to interact with data points in Sylen’s workshop.
Look for the orb
Next, head to the orb’s location. The orb will leave a big trail.
The exact location is shown in the map below, marked by the player location.
Enter the tunnel and continue following the trail.
Examine the orb
You will eventually see the orb inside the tunnel.
Examine it to load the cutscene.
Sylens again appears and explains what he had done so far, and that the GAIA backup is inside the next room.
Open the gene-locked hatch.
Gather resources for the Igniter
As you see some growth blocking the door, you need to get an Igniter to burn the growth.
To craft an Igniter you need to first gather a Leaplasher spark coil from a nearby Leaplasher. You’ll also need to gather weed from the nearby lake.
Once you have the resources, use the workbench near the tunnel entrance.
Head back to the Firegleam and ignite it.
Search the facility for a GAIA backup
Enter the facility.
You will notice a big space and the inner gene-locked hatch is across the water. This part will take some time.
You’ll be required to access a few rooms before eventually making your way to the hatch.
First of all, you will see left and right poles that you can jump on. Go towards the left-side poles. Then, use the pullcaster on a hatch.
You’ll then be able to grapple onto it.
Continue towards the left-side platform, and use the vent above to enter the room.
Inside the room, take the energy cell and insert it near the console to open the door to the next area.
In the next room, you’ll see some plants. Jump up the ledge.
Push the crate forward and drop it on the ground floor.
Then, use the crate and push it towards the ledge. Use the crate to jump on the upper platform.
Ignite the Firegleam.
After the wall blows open, go to the next room to remove the energy cell you inserted earlier.
Bring the energy cell back. You can first insert the energy cell into one of the power points to unlock a chest (optional).
You will get access to an ancient trunk for loot.
Then, take the same energy cell and power up the terminal (another power point).
Once the terminal is up, you can watch the conversation between Sobet and Travis.
Then, use the door to go back out.
As you leave the room, lower the ladder nearby (in case you fall later and want to get back up).
Then, look to the left and climb the ladder up.
Once you’re on the upper platform, use the pullcaster to pull the hatch and unlock a grapple point.
Grapple onto the platform.
From the grapple point, you need to go to the lower platform in the middle.
Just jump and glide down.
Next, climb onto the small ladder and you’ll see another grapple point. Use it.
From the grapple point, glide towards the right-side platform. Lower the ladder you see (in case you fall in the water later).
Then, ignite the Firegleam on the wall to blast the wall open.
Enter the room and you’ll see that you need a code to open another door.
The code is 7482, which is derived from a data point in the room.
Then, continue making your way to the other door.
You will then find yourself outside again. From here, jump onto the pillar in front of you.
As you climb towards the right of the pillar, you’ll see another grapple point. Jump and grapple.
From the next pillar, jump onto the small ledge that is sticking out.
Then, use the pullcaster to pull down a bar.
Use the bar to get to the next platform.
Then, use the pullcaster again to open a hatch and unlock a grapple point.
There’ll be a final hatch to pull down with a pullcaster. Use it to grapple again and you’re finally at the inner gene-locked hatch.
Examine the console
Once you’re in, examine the console in the middle.
Then, examine the inner console.
Find a way to lower GAIA repository
Shoot down the arm of the machine holding the GAIA repository by aiming at the orange glowing part.
Once it’s down, interact with the repository.
Kill the mysterious attacker (Erik)
During the cutscenes, you’ll be introduced to new potential enemies who have access to even higher tech.
They seem to have a clone of Elisabet with them.
You can try to attack him but all attacks will miss. Just run around first.
Use the console
Then, head to the console to try and release the machine.
Shoot the recluse spider arm couplings
As Erik attacks you continuously, you need to run around and shoot at the arm couplings that are glowing in orange. They will appear from time to time.
Shoot the recluse spider stem couplings
Once you’re done with that, you have to shoot at the spider stem couplings which are glowing in yellow.
Take them all out and a cutscene will load.
Search for a way out
After Aloy falls down the platform together with the machine, sentinels will come to kill you.
You’ll have to dive into the water and make your way to the next area.
As you surface in the next area, you’ll immediately see Sentinels.
Dive again and look for a place to breathe (image below).
Then, head underwater again and look for a door underwater that you can open.
Head inside and surface. You’ll reach a small room. Use the pullcaster to open the vent.
Enter the vent and head to the next area. You’ll have to dive again.
Look for another door underwater.
In the next part, you’ll find yourself in a place where you have to climb up.
There’s a vent you can go through.
You’ll reach another door.
In this next room, look for the Firegleam on the left-side wall.
Ignite it and a cutscene loads.
The quest ends after all the cutscenes.