Duty Calls

Duty Calls is a main quest in the Fallout 76 add-on Wastelanders.

Background
The next problem to tackle in terms of storming Vault 79 is the so-called Grim Reaper's Hallway: A hallway chock-full of military grade laser turrets designed to eliminate any attacker who manages to get through passive defenses. Paige suggests reaching out to a group of ex-military operators that has been shadowing the Settlers since The Pitt, and sends the residents to the agreed meeting spot, so that they can enlist their aid in the heist.

Walkthrough
You are to meet certain specialists who will help you acquire the needed parts and tools.

You are sent to a designated spot where you are to raise an American flag as a signal. When you do so, the specialists communicate that your signal has been spotted and that you are to head to their location, a ransacked bunker. You enter the bunker and meet the specialists, an army team led by Captain Fields. Other members of the team are Sergeant Radcliff, Sergeant Thompson, and Private Lucky, a dog.

The captain sends you and Radcliff to the RobCo Research Center. You enter the research wing at the research center, and look for "military projects" While you look, a number of robots fight you. You discover that you need a brain and to install it into a robobrain. A suitable brain is found in the Facilities wing, the choice of brain determines the personality:
 * Dias "There's an unusual patterning in the frontal lobe. The discoloration around the area of the pineal gland also gives you pause. Doctor Dias might have an... unstable personality."
 * Gina "If it's possible for a brain to radiate sadness, this one does. The folding of the cerebral cortex is quite complex, however"
 * Greg "This is a truly unremarkable brain, in the best possible sense. Assuming the extraction process didn't traumatize him, Greg Goldstein should be a perfectly normal mind to talk to"

The next step is to prepare the brain for installation. To do that, you might want to first obtain several important hints, found in notes scattered about: With that information, you insert the brain in the container and turn on the machine to prepare the brain.
 * brain temperature should be 41 degrees Celsius.
 * brain PH should be 7, and
 * the brain timer should be set to 3.

Next, you need to find a robobrain dome, also in the facilities wing. When this is done, install the brain assembly in the robobrain, which then activates. The robobrain is then requested to build certain tools in the research center. While you wait, you again have to fight more robots. When you get the tools you return with them to Captain Fields in the ransacked bunker. Fields and his team tell you they will meet you at Foundation, where you report to Paige.