Spoils of War

Spoils of War is a Brotherhood of Steel main quest in Fallout 4.

Detailed walkthrough
Proctor Ingram explains that in order to fully power-up Liberty Prime, they need a Beryllium agitator. The only Beryllium agitator available is located in the Mass Fusion building. Ingram insists that she accompanies you to get the agitator, because her technical knowledge will be essential for the mission. There is a vertibird docked at The Prydwen that will take you to the roof of the Mass Fusion building when you are ready to go. Taking the vertibird officially makes you an enemy of The Institute, failing any unfinished Institute quests you have.

As the vertibird closes in on the Mass Fusion roof, a contingent of synths will open fire. You have a chance to take out as many as you can with the vertibird's minigun for a time. Make use of the various explosive containers spread across the roof. After a period of time, the pilot informs you that the vertibird has sustained a dangerous amount of damage and needs to leave. At this point, you are given a prompt to disembark from the vertibird and land on the roof. Clear out any remaining synths and head inside the structure. Make your way to the upper level, where you can loot the Mass Fusion executive lab password and ID from a desk. The password can be used to access a computer in the office past the desk that will tell you the agitator is located in the basement. Alternatively, you can hack the computer. The ID is needed to use the elevator that will bring you into the building proper.

Use the ID on the card slot in the elevator to activate it. After a short spectacle of riding the elevator down as you look at the Boston skyline, you will load into the building interior. As the elevator slowly descends, synths will teleport in on the various platforms around the room and attack you. As you reach a glass floor, the synths will set off an explosion, knocking out the power and stopping the elevator. You have two options at this point: get the power back on and continue to ride the elevator, or drop down a hole in the floor and fight your way to the ground floor. There are two methods of turning the power back on - you can hack a computer located in a room to the left of the elevator, or climb to the floor above where the elevator stopped and throw a switch, which is located in a room also to the left. Should you choose to drop down to the lower level and ignore the elevator, there are a number of synths in your way as you wind around the various debris-strewn rooms on the way to the lobby. Riding the elevator causes most of these synths to attack you, as well.

Once you're in the lobby, head over to the left to reach the elevator to the reactor level. Swipe the ID card to open the doors, and take the ride down. Take the stairs on the right to get down to the control room. Ingram will stop and ask you if you have enough radiation protection for the task at hand. Regardless of your answer, she will give you 2 Rad-Xs and say that there are probably some items lying around that can help. There are three hazmat suits in the area - two regular, one damaged. One is in the locker room, on a locker's shelf. The other regular suit is on top of a safe in the office under the stairs next to the decontamination airlock. The damaged suit is in a drawer in front of the window of the airlock. Power armor is also a sufficient method of protection, should you be wearing it.

Taking the agitator will activate the security system, which comprises of a handful of ceiling-mounted turrets, a sentry bot, and two assaultrons. If you have the proficiency for hacking, there is a way to disable the security prior to entering the airlock. On the upper left of the room, there is a terminal that will have the option to disable security, but it will fail. Instead, open the security doors from that terminal and ahead across the room and through the doors you just opened. In that room is an inactive sentry bot and a facilities terminal. From there, you are able to disable the security.

Head into the airlock and press the button. The doors will shut and you will be sprayed, which clears all radiation. After the decontamination, the door to the reactor will open. At this point, you will be soaking in a lot of rads, so move quickly and have multiple Rad-Xs applied. Make your way up the scaffolding to the top of the room. There is a gray orb with blue lights, and a button to the right of it. Press the button to turn off the reactor, which will make it possible to grab the agitator from its housing. This is when the security system will enable if you did not turn it off. Make your way back down the scaffolding and out of the reactor room. Press the button for the airlock and wait for the decontamination, which will wipe away all the rads you just gained. Head back to the elevator and ride it back up to the lobby.

As the elevator reaches the lobby, another explosion will go off. The Institute is throwing a last-ditch effort to stop you from leaving with the agitator. This time, however, you have back-up in the form of a Brotherhood of Steel squad. Ingram will tell you to leave as fast as you can with the agitator. You can either heed her advice and run for the exit, or stay and help the Brotherhood finish off the synths. Staying and helping will complete an optional objective.

Regardless of whether you stayed to fight or not, Ingram will stay behind at Mass Fusion, leaving you to take the agitator back to Boston Airport. Once you arrive at the airport, speak to Ingram at the base of Liberty Prime to complete the quest and begin Ad Victoriam.

Bugs

 * You may be booted out of the Vertibird after entering it. Reloading an earlier save and making sure Procter Ingram joins you may fix this issue.
 * It's possible to have Ad Victoriam not be given after completing Spoils of War.
 * Fix: Reload the game to a point before you made the decision to either choose the institute or the BOS. Talk to elder Maxson to make sure you start the quest Outside the Wire and From Within if available. Step into the vertibird to start Spoils of War when these quests are completed.
 * After completion and once back at the Boston Airport, Ingram may remain silent and can't be interacted with (despite the quest marker above her head), thus making the final step of the quest impossible to complete.
 * One possible fix is to reload a save prior to accepting the quest, and during dialogue, insist to go alone to Mass Fusion building. She will stay at the airport and can be talked to when the mission is complete.
 * PC players can use the following console command to set the quest as completed: setstage bos303 255