Inspiration:
The Defector
The Chase
The Enterprise Incident
Picard Maneouvre
Movie opens with the Enterprise and other ships in orbit around a new Vulcan colony. Federation fleet ambushed by a Romulan fleet (imagine if they'd shown us the battle of Vulcan). Big battle in space. Federation aircraft carrier, larger than enterprise is dramatically destroyed. Enterprise defeated, left damaged Star Trek II style. But the Romulans aren't interested in the Federation fleet, they beam down, the Romulan Commander kills elder Spock in front of Kirk (who was on the planet) in dramatic fashion, and take Sarek and some other Vulcan elders. They're holders of some sort of important historical secret. This opening serves to establish these Romulans as bad mofos. They warp away.
One Romulan ship is damaged and left for dead. The Enterprise rescues a Vulcan female hostage from among the prisoners. There's some sexual tension between her and Spock, centering around the fact that she's a real Vulcan female, and since the Vulcans are almost extinct, he should leave Uhura, since she's a lowly human. He owes it to the Vulcan race. Drama between Spock and Uhura. From this rescued Vulcan prisoner, Kirk gets some info on what the Romulans were after. Apparently, they are after some sort of ancient super weapon left behind by an alien race, and they need clues from the former planets of this ancient empire to find their ancient capitol. The empire existed before the time of Surak, and the Vulcan elders have retained some ancient knowledge about them, in the same way the Greeks know something about Atlantis, but they don't have all the details. The Enterprise repairs, and the Vulcan girl agrees to help them figure out their next move.
A chase begins a la, TNG the Chase. Kirk is beaten by the Romulans again at the 2nd planet with clues. Turns out that the female Vulcan prisoner is actually a Romulan (half Vulcan, half Romulan) double agent! The Romulans are waiting and beat the Enterprise again. Her "rescue" aboard a derelict Romulan ship was staged so that she could steal some information from the Enterprise computers about what the Romulans are really after. The ancient civilization's territory extended over both Federation and Romulan territory. The whole 2nd planet thing was staged to provide her a means of escaping to a Romulan ship. She kidnaps Spock when she gets away.
But Kirk and Spock, smart mofos that they are, knew that she was a double agent, and allowed her to escape. And even though the Romulan ship cloaks as it escapes from the 2nd battle, Kirk knows that Spock will send a signal to allow the Enterprise to track them. They were ready, and the Enterprise was only playing dead.
Meanwhile, Spock is hostage aboard the Romulan ship. There is some sexual chemistry between this Romulan Commander and spock a la 'the enterprise incident'. His fidelity to Uhura is tested. This girl is mean. Think like Juliet when we are first introduced on Juliet on LOST. She can be nice one minute, and then beat the crap out of Spock the next if he is uncooperative.
The Romulans go to the real they were looking for in the Neutral Zone. Spock, the Romulan girl double agent, and her superior go down to the planet in a shuttle. It's one of those planets where transporters don't work.
The Enterprise arrives while they are on the surface. This time the Enterprise does the ambushing, fights a pitched battle against the Romulans but beats them by inventing the Picard maneuver before Picard does and wins, but it won't matter if the Romulans get their hands on the ancient super weapon from the extinct species. Kirk takes a shuttle down to the planet with McCoy & maybe some others.
There's some hand to hand combat, Kirk vs the main bad dude, amongst some alien ruins in a dramatic alien landscape. While they're fighting, they discover the secret . . .
The ancient civilization, ancient empire the never went extinct, they had simply moved on to the next phase of evolution and had moved so beyond empire and had such infinite, omnipotent knowledge, that they were above this puny conflict between the Federation and the Romulans. As Spock says in Star Trek I, "possibly a next step in our evolution." They impose something like the Organian Peace treaty on the Federation and the Romulans, at least within their system and send everyone on their way.
Movie ends on a positive note like TNG the chase, where the 2 commanders talk to each other and say "one day"
Best fan fic I've ever read ...