The New Arrivals

The New Arrivals is a main quest in the Fallout 76 add-on Wastelanders.

Quick walkthrough
Talk to the Vault 76 overseer at her home. Complete Strange Bedfellows and Here to Stay. Return to the overseer, and brew an inoculation against the Scorched Plague at Kanawha Nuka-Cola plant. Deliver the inoculation to Meg and Paige. Return to the overseer to complete the quest.

Detailed walkthrough
Upon the quest first starting, tune into the Overseer's radio station on the Pip-Boy 2000 Mark VI, where she will ask all Vault 76 residents to meet her at her new home in Sutton. Upon arriving there, the Overseer's home can be found on the hill overlooking town to the east. Upon entering, the Overseer will invite the player characters down to the basement, introducing them to her Mr. Handy assistant Davenport, and also inquiring as to if they completed their original mission from her regarding the Scorched Plague. Her reasons for asking about the inoculation are due to her concern about the new factions that have come to Appalachia. She asks the player characters to travel to Foundation at Spruce Knob to speak to the leader of the Settlers, and to talk to Rose about getting in with the Raiders at their new main settlement, The Crater, at the crashed Valiant-1 space station, so as to give them the inoculation against the Scorched Plague. If they fall victim to the Scorched and Scorchbeasts, it could be the events before Vault 76 opened all over again with the Scorched and Scorchbeast Queen able to get beyond Appalachia's borders to spread their influence due to a lack of cooperation between the various groups.

After the Overseer asks the player characters to get into the Settlers and Raiders, the quest will not advance until after completing the first quests for the Settlers and Raiders, "Here to Stay" and "Strange Bedfellows" respectively.

Once Paige and Meg have agreed to allow the Settlers and Raiders to be given the inoculation, report back to the Overseer, and she'll realize the best way to get the inoculation mass-produced is at the Kanawha Nuka-Cola plant southwest of Charleston.

Head over to the Nuka-Cola plant, take out the low-level feral ghouls outside, and head in to meet up with the Overseer. Fight through the high-level feral ghouls inside, possibly even a glowing wendigo or a couple of legendary feral ghouls, which if "Officer on Deck" is still active, will count towards the commendations, and in one room, have the player characters step into the scanner to have their blood scanned as a sample for a new Nuka-Cola flavor, then use the device at the other end to mix the blood's antibodies into the formula. Don't worry about the Overseer. Due to her being marked essential, if the feral ghouls down her, she'll recover after a few seconds.

Once that is done, head over to the plant reactors, and depending on the player characters' SPECIAL stats, new power couplings will have to be found to replace the old ones, or can be jury-rigged to work around that. Once the reactors are back up and running, deal with a few more feral ghouls, then use the computer in the upstairs room to set up the manufacturing process. Once a new name for the latest Nuka-Cola flavor has been selected, along with an age group, garnering some witty banter from the Overseer, head over to the manufacturing machine and hit the button to start the assembly line. After a few seconds, freshly-made Scorched Plague inoculation Nuka-Cola will roll out of the machine, ready to be collected. Satisfied with now having a means to prevent the spread of the Scorched Plague among the newcomers to Appalachia, including the Settlers and Raiders, the Overseer remains behind to continue making more of the inoculation while the player characters head out to deliver the first batch to Paige, Meg, and all their people, then report back to the Overseer's house in Sutton for a progress report.

After handing the inoculation over to Paige and Meg, who thank the player characters for ensuring their people don't become the next victims of the Scorchbeasts, the player characters return to the Overseer's house to report mission accomplished, before the Overseer has another request, this one regarding the reasons why people are migrating back into Appalachia: The treasure rumors. According to her, several other Vault 76 residents found another Vault in the mountains: Vault 79. She intends to investigate it further by traveling to Vault-Tec University in Morgantown to gather more information, and asks the player characters to meet her there. This completes the quest and starts the next one, "Overseer, Overseen".

Davenport will also be available to talk to as a miscellaneous objective to start a daily quest as well focusing on the Settlers and Raiders.