I was thinking of the group being 'survivors' from the different raider groups who had been left alive after the "kill-all" order had been sent, and who had blacked out for several hours before waking up to find themselves covered in their friends' blood and viscera.

After hearing stories of Synths having attacked people at random at roughly the same time as the blackout some of them would've put two and two together and realised the truth about themselves, but given the hellscape they lived in decided to ignore the truth aqnd keep on raiding. Of course given that raiders aren't the most gifted intellectuals, some would've put two and two together and realised they must've had some really good chems before the blackout and now want to find out what the hell they were so they can get more.

How long did the signal last for, and did the sleepers return to a stable mode once it ended?