the game starts a couple hours after dead space 2 ends, with isaac and ellie in the gunship but they suddenly take fire as a derranged earthgov captain and his surviving soldiers come by in a gunship. isaac shoots back and both ships are shot down into a nearby colony. it is revealed that the earthgov captain has an infector in frozen capsule and shoots all of his soldiers and releases the infector in the gunship as the captain flees (isaac and ellie witness this through a video transmission). isaac and ellie go to the colony to warn them but discover a majority of the colonists are unitologists and are killing many non-unitologists. as isaac and ellie are about to be taken to the "overseer" they are saved by a mysterious figure who takes them to a secret place which is only accessible with a keycard which there are only 2 copies of. there is medical equipment there and a pregnant woman who introduces herself to be..... Lexine! and the mysterious figure is revealed to be Nathan McNeill.
-new features= 2 player co op mode with isaac as first player and second player as either McNeill or Ellie (it's two player so it makes it realistic because someone has to stay with Lexine)
-secrets revealed= who is the elusive overseer? how did Lexine get there? why was McNeill never mentioned in DS2: Severed DLC?