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After having an unexpected encounter with Dani, Jacob starts off the fourth chapter of The Callisto Protocol with a plan of action. He needs to meet up with Elias inside the Habitat Dome before they head to the hangar. Of course, in order to get there players will need to go through a long underground tunnel that runs between Black Iron Prison and the Habitat Dome.
Since this is a survival horror game, players should not expect an easy trek through the underground tunnel as it is infested with Biophages. To make matters more difficult, there is a new type of Biophage that players will need to watch out for. Here is what to expect in the fourth chapter of The Callisto Protocol, Habitat.
This walkthrough contains spoilers, so players should proceed with caution.
Find a Way Past the Door
As players approach the door to Water Processing, they will see a hologram of Elias. He will talk about a red pipe that goes all the way from Tank 6 to the Habitat Dome. This red pipe will help Callisto Protocol players with navigation, so make sure to look for it when in doubt as to where to go next.
The door to Water Processing is rusted shut and the only way to proceed is to go through the vent on the right. After emerging from the other side of the vent, players will find themselves wadding through a large pool of sewage. There is a Biophage lurking in the water, so players should be careful as they move toward the crank that will open a vent that will lead out of that room.
How to Get Past the Door to Purification B H207
It isn't long before players come across another hologram outside the door to Purification B H207. The door is sealed shut, and the only way to get past it is to use the vent on the left that will lead into the room. In this next area, players will need to locate fuses that are on boxes and insert them into the panels throughout the room.
While gathering the fuses, players will be ambushed by a new type of Biophage. It runs around on all fours and barely looks anything like a human anymore. These new Biophages move fast, and they can turn invisible, so Callisto Protocol players will need to keep an eye out for any movement. Despite their speed, their attacks can easily be dodged. Once all fuses have been placed, players will be able to enter Access Hall H271.
How to Enter Access Hall H206
As Callisto Protocol players progress through the next area, they will see the red pipe. Follow it to reach a ladder that goes up and out of the sewage. In the next area there are several Biophages and a locked door that leads to Access Hall H206. In order to open the door, players will need to find a fuse.
Look around for a ladder on the right side of the room, it will lead up to a platform where the fuse is. More Biophages will show up when players grab the fuse, so they should prepare for that. After dealing with the Biophages, move on through Access Hall H206 and enter a large room.
Find the Guard's Code
In this next area, Callisto Protocol players will see another hologram of Elias. In order to clear out Tank 6 and use the pipe to go to the Habitat Dome, a purge cycle needs to be initiated from the console in this room. However, it requires a keycode that only the guards have.
To find the code, players must go through the door on the south side of the room. From there, go through the hallway to Lounge F231. Once players go past the body on the wall near the lockers, they will be ambushed by a Biophage that introduces the mutate mechanic.
When a Biophage begins to mutate, players must shoot or hit the spot with the tentacles to prevent the mutation. Failure to prevent mutation results in a much more powerful Biophage that will have a lot more health and do significantly more damage. To prevent this, players will want to make sure to shoot or hit them with the upgraded Stun Baton as quickly as possible. After killing the Biophage, grab the code from the guard in this room and go back to the console to initiate the purge cycle.
Deal With the Biophages
Naturally, starting a purge cycle draws the attention of a lot of Biophages in the area. Players will have to deal with several Biophages at once, so they will need to move quickly and dodge whenever possible. After all the Biophages are dead, the cycle will complete and the console for the bridge can be activated. Across the bridge there is a ladder that will allow players to go into the pipe that they drained. Before proceeding, make sure to turn around and grab the Callisto Credits that are in the dead end.
Flushed
As Callisto Protocol players proceed down the pipe, a cutscene will play where the water returns and flushes them down the pipe at a rapid pace. During this sequence, move to avoid getting hit by the pillars and spinning fans. Near the end of this sequence, there will be several QTEs to shake Biophages off as well. If players successfully survive this section, they will get a story related achievement/trophy.
Enter the Dome
Climb up toward a door in the circular room. There is a few Biophages in the area, so players will need to deal with them first. After that, move through the door to reach an elevator. Before moving on, make sure to look around for supplies. Once players leave the elevator, they will arrive in the Habitat Dome.
Upon arriving in the Habitat Dome, Elias tells Jacob that the tram cannot enter the Habitat Dome until the lockdown is lifted in Oxygen Processing H623. This isn't far from where players start, but they will need to move carefully as there is a Security Unit patrolling around the area. Avoid it at all costs as it does have an attack that can one-shot players.
Get Another Code
In order to lift the lockdown, Callisto Protocol players will need to find yet another code from a guard. The code is on a body that is out of reach. In order to get it, move through Oxygen Processing H625 and look for a vent with blood around the bottom edge. This vent will lead players to the guard that has the code. Open the door and use the code to end the lockdown.
Rendezvous with Elias
Go back out into the Habitat Dome and move toward Utility H630. The platform is broken, so players will need to go across the middle part to reach the door. There are several Biophages in the area, so players will need to deal with them. In the next area, there are lots of environmental hazards to watch out for. To make matters worse, players are attacked by a large group of Biophages once they enter this area.
Use the GRP and launch enemies into hazards around the room to save some ammo, and make sure to dodge whenever possible. Once it is clear, crawl past the lumber and boxes to reach a broken platform where Elias is standing. Once players climb up the ladder, a cutscene will play and the fourth chapter of The Callisto Protocol will come to a close.
The Callisto Protocol is out now for PC, PS4, PS5, Xbox One, and Xbox Series X.
