If there's one lesson you should take away from the story trailer for Call of Duty: Black Ops 3, it's: don't ask someone to turn you into a killing machine if you don't want to be, you know, a machine.
From what I can tell, the theme of the latest Call of Duty game is "be careful what you wish for". I predict a game at war with itself, trying to tell a cautionary tale about future technology while also giving you lots of cool future technology to play with.
At one point a character says, "Your mind truly is your greatest weapon," which sounds progressive but is actually to do with the fact that they've literally weaponised some guy's (presumably a playable character) brain through a "direct neural interface". What could possibly go wrong?
It's difficult to get past the line "we wanted a perfect future, and fuck, we got it" without laughing, but after that you can actually get some story details if that's your kind of thing. Your task in the single-player campaign is to find out what's happened to your missing brothers (presumably military, not familial). Here's my prediction: they also had direct neural interfaces, which led them to get mixed up with your enemy, and yours will also go wrong at some point, and we'll all learn a valuable lesson about not trying to control people's brains.
Sound a bit heavy for you? Don't worry, there'll also be zombies.