Commander Daguerre detected a USSA signal in Appalachia. Two, in fact, except when the two encountered each other, only one remained. She asks the Vault Dweller from Vault 76 to investigate the signal for trouble and deal with any possible threat.
This is a simple kill assignment. As with every other storyline quest with Sofia, this one unlocks a new conversation, allowing the player character to inquire about floating in space, the reasons behind the USSA robots trying to hunt her down, and suggest taking a walk (she already did and even encountered Grahm).
To complete the quest, one has to go to Dyer Chemical and kill the USSA assaultron. Its stealth capability was responsible for the erratic signal Daguerre picked up. Even worse, it has been hunting down USSA astronauts.
Upon return, Sofia will be found alongside Doctor Emerson Hale. He is an old acquaintance of hers, and she will explain her situation to Hale. Emerson is camped out at a nearby military base and will reveal that he set up the beacon, hoping to hand over the monitoring of the Deep Sleep mission to someone else. He claims to be lucky to have found the escape pod.
Despite his suspicious behavior and recommendations to forget about Deep Sleep, Sofia will still trust him. He will reveal that dealing with the headaches could require an emergence kit, which was a standard issue for Deep Sleep missions. He reveals that the USSA robots used to come after him until they picked up a higher priority target, that being Sofia. He will also suggest expanding the scanner to monitor for targets moving at a constant speed, to track down and intercept the robots.
Talk to Sofia again to complete the quest. She will explain that she managed to isolate the signals from the flight suits of her crew and ask the player character to investigate them. One can ask more questions, including a Perception 4+ option about Unstoppables comic books she used to read (adding an issue of Unstoppables 1 to the player character's inventory).
[verification overdue]When you return to talk to Sofia, if your camp has turrets they may drive off Hale causing the conversation to stall when he is supposed to make his first statement. This can be fixed by temporarily storing the turrets or moving her console away from the turrets, then fast traveling away and back to start the dialog over.
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