Let me write the first few episodes of Season 2 for y'all:
Premiere starts with E-reps in control of Defiance, Datak and Stahma are under arrest and pending summary execution and things look grim. At least one if not a couple of hours of token resistance fighting from various members of the townsfolk trying to rescue (reluctantly) Datak and Stahma along with the Mayor finding out about her dead sister. The resistance has taken up residence in the ruins of St Louis underground and is fighting a losing battle against the military forces of the Earth Republic. The Heroes look to be royally fucked and about to all be killed by evil bitch queen Erep ambassador when...
EARTHQUAKE!! The ground shakes all over the area, the arch even gets a significant crack in it and everyone is looking around confused. Suddenly a massive Votan-esque but not necessarily Indogene looking ship bursts out of the mountain. Irisa is back and she is in command of the 4000 year old mega ship and tells the Ereps to go fuck themselves. They try to hold Nolan etc hostage and get eradicated instantly before the remainder of their forces run. The ship hovers over the Arch and Irisa declares Defiance to be under her protection.
Rest of season involves the characters trying to figure out what exactly the super ship is, how it got to earth thousands of years before the fleet and why. Oh and the ship starts to communicate with everyone through a hologram interface that just so happens to take the physical form of the Mayor's dead sister. By the end of the season we learn that most of Native American spirituality actually stems from Irathient mysticism and that Native Americans like the Macaully family are actually descended from Irathients many many generations removed. Turns out humanity and the Votans are more interconnected than either of them thought...