Okay, PoI fans... (season 3 finale spoilers kinda)
Serac was totally Greer in God-mode the whole time!
And Solomon (The Machine) took out Rehoboam (Samaritan) by trojan horse-ing itself through Dolores because its "flawed" programming could think outside the box more freely than the more "sane" Rehoboam.
The First Outlier (Solomon/Jean Mi) was the real threat to Rehoboam all along - not Dolores.
I wonder..the EMP didn't wipe Dolores or Maeve, so does that mean Solomon could be rebooted? We know Rehoboam is gone, but is someone going to get a phone call?