The Catalyst is the fifth and final quest in Fallout 76’s DLC Steel Reign that completes the storyline with some interesting twists and gameplay choices. Once you have completed the “A Satisfied Conscience” quest, you will eventually return to Fort Atlas and report to the Brotherhood Leadership. There, you will witness Knight Shin, Scribe Valdez, and Paladin Rahmani interrogating Dr. Blackburn.
During the conversation, you will learn that Dr. Blackburn’s associates are carrying out the plan to spread FEV. After that, you will be tasked to reach the West Tek Research Center and stop the malicious activities there. There will be multiple rewards for completing this quest, including the Hellcat Power Armor and Steel Brethren Achievement.
Below is a complete walkthrough of The Catalyst quest in Fallout 76, including all of its major objectives, the best choice, and quest rewards.
Enter the West Tek Research Center
As the conversation at Fort Atlas ends, fast travel to the West Tek Research Center. You may encounter Super Mutants outside the Center building.
You can either engage them or slip by them using stealth. The next objective will take you to the Research Wing.
Gain Access to the West Tek Research Wing
As you approach the West Tek Research Wing in Fallout 76, you will require the terminal password. For the terminal code, go to the Dispensary Lab and interact with its terminal. You’ll learn that the lab will only be accessible if you approach the control room situated upstairs.
The path to the ahead also contains a few super mutants. Enter the control room (by following the objective marker) and select the “Open Door” option from the terminal. This will open the Dispensary Lab for you.
Having entered the Dispensary Lab, get the access code for the Research Wing.
Now, head to the Wing’s terminal and Open the door using the code you just acquired.
Access Dr. Blackburn’s West Tek laboratory
After going inside, a new objective will be updated. Use the elevator on your left to reach the FEV Production Facility. Once you are outside the lift, go straight and you will find a metal door.
Defeat the Mercenaries & Regroup with the Brotherhood
Go through the metal door and you will encounter a Hellcat Mercenary. Eliminate him and go through the door on the other side of the room. Now you will encounter three more mercenaries. Now, the rest of your team will come along with Dr. Blackburn.
Speak to Dr. Blackburn’s research associates
Follow the Brotherhood down the path where three scientists (associates) are working behind some protective glass shield. During the talk, you can use Strength 8, Endurance 8, or Intelligence 4 to persuade them to stop releasing FEV on the population. Dr. Blackburn will eventually be released so that he can use the access code only he knows to stop the virus.
Wait for Dr. Blackburn
Once he is inside the facility, Blackburn will declare that he does not plan to make good on his promise. He will betray you and will use himself as a Test Subject. Be patient for now, as your time to punish him will come soon.
Drop through the hatch & Witness the experiment
Dr. Blackburn is quite eager to show everyone that he has produced the perfect specimen through his experiments. Paladin Rahmani and Knight Shin will say that something should be done immediately to stop the madness. Look for a hatch nearby and drop down through it to witness the experiment. Blackburn will turn into a Super Mutant by using his sample.
Defeat Blackburn
Dr. Blackburn will go berserk after the mad experiment on himself. He will attack you with all his might using the beastly body and a giant sword.
Beware of his acid attacks too, which will be recognizable through their green color. Even if you are not adept at Fallout 76’s enemy encounters, you will probably win the fight as Knight Shin and Paladin Rahmani are covering you.
Gain access to scientists’ viewing chamber
After eliminating the doctor, follow your team to the scientist’s viewing chamber door. After a while, Dr. Farah will let you in once she has ensured her and her team’s safety from the Brotherhood.
Deal with Dr. Blackburn’s Associates
Once you can, go inside and talk with the scientists; after the conversation ends, talk with everyone in the chamber individually, including Shin and Ramani. As usual, both of them will be at loggerheads about how to deal with associates. Rahmani wants to spare the scientists and take them to Fort Atlas so the Brotherhood can take advantage of their knowledge. However, Shin wants them dead on the spot as they may keep producing lethal viruses that can eliminate humanity.
The Best Choice – Side with Rahmani
Now, you must decide whether to side with Paladin Rahmani or accept Shin’s proposal.
Siding with Rahmani is the best choice at this point in the Catalyst quest of Fallout 76 Steel Reign. She makes more sense than her colleague does. Killing the scientists on the spot will leave no room for gaining their knowledge, which could be used for the benefit of humanity.
Once Knight Shin learns that everyone is against his decision, he leaves the chamber in anger to report everything to the elders. You can also Kill Shin to stop him with Rahmani’s help.
Regroup at Fort Atlas
Afterward, return to the Fort Atlas and listen to Rahmani’s address. She will announce that Knight Shin has left Appalachian Brotherhood, and then name you the Knight-Errant. After that, speak with Scribe Valdez and Paladin Rahmani individually and then speak with everyone in the hall.
Finally, speak with Rahmani again, which will mark the ending of the Catalyst quest in Fallout 76 Steel Reign.
Fallout 76 Steel Reign The Catalyst Quest Rewards
After getting over the Catalyst quest, the reward will be the Steel Brethren achievement, i.e., for completing the Steel Dawn and Steel Reign storylines.
The second reward you receive is the Hellcat Power Armor. You will also receive some caps and XP, just like you get for completing other quests.