Oh did someone say spitballing? Let me get coked up here.

This MacGuffin crystal, let's call it a starseed; say it can terraform a planet and replicate genetic code. It's big, Dark Crystal size-ish. (Khan is not a Skeksis.)  The sparse population of Niribu dudes worship it; Dr. Marcus and her team have been studying it awhile from a Prime Directive-preserving distance on a science station. There's nothing else like this thing, it's unbelievably old and advanced. However, it's damaged and weakened and faded, which is why the planet is falling apart. The Enterprise has arrived to help. Carol and Kirk hit it off, and in private she tells him about the starseed and how she wishes she had more time to study it, she wishes she could get it in her lab, and her dreams for what can be learned from it. Kirk likes her brilliance and vision and the scale of her dreams. Such things are rare, especially in the Abramsverse. (What are Kirk's dreams? Does he just point out the viewport at the Enterprise? "Her, and where she'll take me"?  Maybe young Dr. Marcus finds that sentiment romantic.)

So maybe a bigger fucking-up on Niribu is in order. Spock wants to try a suicidal last-ditch thing to stave off the crust breaking up. Kirk says no way, and swooshes the Enterprise in, gets Scotty to miraculously mass-transport the small native population of Niribu up into the Enterprise, filling it up to the gills and fucking up the warp drives in the process by overloading the transporter, and gets Spock out too, and oh yeah gets the starseed crystal as well, maybe hitching it to a shuttle and riding it up out of the lava storm like a reverse Slim Pickens with Sulu at the wheel.

Back at Starfleet HQ, Kirk's all smug that he saved his buddy Spock, and the Niribu people, and plus got this sweet gift for Carol--but it turns out everyone's pissed off at him. (Except Bones, who is sympathetic but bluntly critical of course.)  Even Pike is disapproving and, as it turns out, didn't defend Kirk much in the mission review. "Don't thank me, thank Admiral Robocop, he backed you up way more than I did."  Pike is tired of sticking his neck out for Kirk. On the other hand, Peter Weller likes what he sees, and Kirk recognizes that Robocop has more pull than Pike (and might be a future father in law??), so Kirk and Pike half-end their mentor/protege relationship. Sure, Pike even says, "Don't say anything you'll regret" and Kirk then says that thing. Then Pike is horribly mutilated in the attack and Kirk feels bad about that.  Weller's like, "aha, perfect catspaw" and gets Kirk to take the torpedos on this special little side mission.

Khan has fled deep into Klingon space. By stealth shuttle FFS. Kirk decides not to activate the torpedoes. As it turns out, Uhura knows the shit out of Klingon customs and is able to pass herself off as a bounty hunter or smuggler or something. (Spock: "I didn't know you were such a skilled liar." Uhura: "That's how it works.")  It's not the homeworld, security is not insane. They meet a real Klingon spaceship on the way, bluff past it, and never fly sideways through any junkyard smashers. They pick up Khan, who is surprised but surrenders willingly. While captive, Khan slags Admiral Robocop and Starfleet up and down, explains how he's just using Kirk to escalate the situation with the Klingons, that of course he wouldn't miss the chance to use his new toy torpedos, did Kirk bring all 72 by the way?  ("*scoffing* Robocop thinks every situation calls for overkilll." "And how much killing have you done, Khan?" "The numbers are exaggerated. Millions--but I was just getting started.")

I can't think of how Khan's diabolical plan shifts and adjust and unfolds, but it winds up with the torpedos getting launched from the Enterprise, against the good guys' wishes. Instead of going off to Klingon space start a war, though, they veer around and smack into the Killerprise, where Khan is held captive. Khan's quick-thawed ubercrew pop out of the torpedoes and take over the ship. (Khan: "This was always my ship. *squish*")  The Enterprise rut-rohs and runs. The Killerprise chases the Enterprise in and out of warp. Maybe they <i>could</i> just fuck off the other direction and let the Enterprise go get help, but Khan really just has contempt for Kirk and wants to crush the Enterprise like a bug and gets angrier and angrier when he can't. Sulu is flying, Scottie is squeezing last drops of power, Uhura is not happy about getting jammed, Chekhov is aligning shields, Kirk is making decisions and egging people on, everyone is doing their job well.

Is it too pat if the Enterprise lures the Killerprise back to <strike>Naboo</strike> Niribu and makes it crash into the planet?  The Enterprise crew knows all about the screwed up orbit and/or magnetic fields because they're the ones who did it, but Starfleet hasn't updated their charts yet.. So they calculate and guess and it's near suicidal, but they come out of warp super perilously close to the planet, and whups the Killerprise plops into it. Fucking tailgaters.

Alt ending: At least two bridge crew characters die. Uhura and Bones, let's say. Dr. Marcus is right over there at the science station with the starseed and everything. The Enterprise limps over, and they rush in to talk to her. Kirk reminds her of what she said in the beginning of the movie, how maybe the crystal could capture someone's consciousness, regenerate their bodies, how it was meant to heal, not harm. Crying, she says that's not how it works, it will take decades to figure out, they may never know. It just can't be done. Kirk yells and punches a wall and paces but there is no winning this one, and he sits down in a hallway. Roll credits over angry molten sphere of destroyed Niribu.