Honestly, my idea is that Kirk becomes commodore of Yorktown after getting together with Carol and they start of life there. A threat pops up with the Klingons loosing several ships to this weapon, and them deciding to pull out all the stops to destroy it. Kirk takes a task force to investigate and discovers a Klingon ship based on the Narada tech dealing with the Doomsday machine.think the movie would be most interesting by somehow tying it back to the first one, with some more direct consequences of what had occurred there now creating issues. Maybe riff on the deleted scenes of Nero and the Narada having been captured by Klingons for 20 years, which can also bring in shades of Into Darkness with gearing up for that war Admiral Marcus wanted. Add in a dash of Beyond, with maybe Kirk going rogue or something, because... idk... the Federation was going to abandon a colony world (hell, maybe Yorktown?) to avoid a conflict with the Klingons, but Kirk goes on a stand about how they can't do that.