Plot Twist.
Episode 3 has flood.
Tired of killing promethians and covies.
/gamechanger
Bigger plot twist: Cortana isn’t dead. 
Biggest plot twist of all,
Didact is Sgt. Johnson
> Bigger plot twist: Cortana isn’t dead.
Mind = Blown
Maybe the promethians are the new flood. I mean from what we saw this episode,one scientist got sucked into the artifact and we heard a science team that may have suffered the same fate.
I don’t know how because we destroyed the composer, but maybe the science team at Gargarin were turned into promethians.