synopsis
Warning! Spoilers Ahead!
Kirk's dad dies during a touching moment where he talks his wife through the birth of James T. while ramming his starship into the evil badguy mining ship. Everyone cries. Evil mining ship waits around 25 years for Spock to appear from a black hole. Spock carries around instant-black-hole juice for all of your galaxy saving needs. Meanwhile Captain of the Enterprise (Pike) finds Jim Kirk getting into a bar fight, and promotes him to Captain. The Death Star blows up Vulcan, then Spock becomes temporary captain and hates Kirk, so he sends him to Hoth where he has to run away from an evil taun taun. Fortunately he runs into Future Spock, who introduces Kirk to Mr. Scott and his Midget Wookiee.
Future Spock recursively gives Scotty a magic equation that he has yet to invent himself, and they transport back on to Enterprise, where old new Spock and Kirk get into a hissy fit. Kirk wins the debate, so he becomes captain, and they become best budz. Spock gets into his X-Wing and flies down the canyon, but photon torpedoes merely graze the surface.
So the Enterprise hides behind Saturn to ambush this Death Star/mining ship (i'm really not making this up.) Kirk has to go on board the Death Star and fight a very handsome sneering bad guy (played by Eric Bana). Bad guy has Mike Tyson tatoo and whines about his planet being destroyed or some crap. Kirk like punches him real hard and his ship blows up. Earth was saved.
Destroying the mining ship created a black hole (of course), so the Enterprise just
barely gets away, even at full warp. I don't know what sort of effect on the solar system having a random black hole next to Saturn would have, but I guess that's what sequels are for! At the end of the movie, Kirk gets a medal from Princess Leia.