The world changed and no one knew about it. The eternals that remembered they were Eternals went back to Olympia. Then an army of Deviants came lead by Kra . We then go to see Sersi and Tony Stark talking about how she should come back to being an Avenger but since she barely remembers it she declines. Then we see Zuras telling Makkari that he will be the one to deal with the deviants, but Druig decides not to listen and attacks all deviants in sight which brings on the battle.
Then we see Sprite who is on a tram to get on a plane to see his dad then Zuras shows up and because of what he does and he is mortal now he snap his neck. Then we go back to the battle which is basically the deviants realizing he is the Skadrach the eternal fused with the Celestial. Since he will bring destruction wherever he goes the deviants decided to leave him alone. Then we see Zurus tell Makkari and Ikaris to go find the other ninety eternals to fight the horde that the celestial summoned and that is the end of the eternals saga or maybe a beginning.