Star Trek (film)/Summary/Act Three

Following his outburst, Spock returns to the transporter room, where Sarek tries to get Spock to open up to him. Spock admits to feeling conflicted and feels a rage he cannot control towards Nero over the death of his mother. Sarek offers that his mother would have said not to bother controlling it, and, recalling what he had said years before after another outburst of his son's Human side, sadly admits to his son that he married Amanda because he loved her. 
Meanwhile, on the bridge, Chekov figures out a plan to get the Enterprise close to the Narada without them noticing: they can follow the Narada and stop at Titan's orbit, remaining undetected by hiding in its magnetic field. Soon after, a cooled-off Spock returns to the bridge, confirms the logic of Chekov's plan, and offers to beam over to the Narada to get the "black hole device" and save Earth, the only home he has left. Kirk says he will go as well, to rescue Pike. Spock mentions regulations against the captain and first officer going on such a mission, but chooses not to cite something he knows Kirk will ignore. Kirk quips that they are finally getting to know each other and gives Spock a friendly slap on the shoulder.
The Narada has already arrived at Earth and deployed its drilling rig directly over San Francisco. Warping into Titan's atmosphere, the Enterprise remains undetected by the Narada. Before stepping onto the transporter pad, Kirk calls the bridge, telling Sulu that, if he believes the Enterprise can destroy the Narada, even if Kirk, Spock, and Pike are still aboard, he should not hesitate to take the opportunity. Sulu reluctantly acknowledges Kirk's order. 
Before they beam over, Uhura kisses Spock and tells him that he better come back. In his reply, he calls her "Nyota." Kirk, who overheard, then asks Spock if that's the first name he had tried and failed to learn since the first time he met her; Spock coyly cuts him off, stating his refusal to comment on the matter. Right after they are beamed aboard, the Narada begins to drill its hole near the Golden Gate Bridge, cutting the ship off from the Enterprise and disabling transporter functions.
Scott thought he could beam Kirk and Spock to the Naradas cargo bay without being seen, but it turns out to be a heavily occupied portion of the ship. After a brief firefight, Spock uncovers the location of the black hole device and Captain Pike by melding with an unconscious Romulan. When they board the Jellyfish, it recognizes Spock as its captain (at which Kirk sarcastically expresses surprise), and the Vulcan finally figures out what is going on, as the ship's computer confirms its origin stardate as 2387, constructed by the Vulcan Science Academy. 
Spock confronts Kirk about withholding information from him, but Kirk dodges the question by asking Spock if he can fly the spacecraft, a question he is fairly confident Kirk already knows the answer to. For the first time, Spock calls Kirk, "Jim" and informs him that their chances of success are grim by citing his calculation of their odds, but Kirk assures him that their plan will work.
Spock commandeers the Jellyfish and blasts out of the Narada. Spock uses the ships guns to destroy the drill's tether, plunging the platform into San Francisco Bay. Kirk runs into more trouble as he finds the Romulans' "bridge", where Nero and Ayel are waiting. Kirk is confronted by Nero, who has recognized him from Earth's history, and after a brief scuffle, Nero pins Kirk and tells him that, while he was a decorated officer and went on to captain the starship Enterprise, that was another life, and that he plans to deprive him of the same life his father once had.
Before he can finish Kirk off, however, Nero is informed that the Jellyfish has been stolen and the drill has been destroyed. Furious above all else, Nero storms off, leaving Kirk to Ayel while he plans to kill Spock. Ayel promptly grabs Kirk by the throat and lifts him in the air, surprised at how "weak" Humans appear to be. Seeing his prey attempting to talk, Ayel offers Kirk the chance to say something – and the Human replies that he is in possession of the Romulan's disruptor pistol. Kirk fires and kills Ayel as he plunges into the depths of the Romulan vessel. He then heads off to rescue Pike. 
On the bridge, Nero hails Spock, declaring that he should have killed him when he had the chance. In reply, Spock taunts Nero by "ordering" him to surrender. Nero orders the Jellyfish destroyed, even though the ship still has "red matter" on it; with his plan for revenge ruined, now he only wants to kill Spock. The Jellyfish evades the missiles, then goes into warp, with Nero and the Narada in hot pursuit, leaving Earth behind.
When the ships drop out of warp, the Jellyfish turns to intercept and collide with the Narada, seeking to ignite the red matter and create a hole that will envelop both ships. Nero panics and orders all weapons fired, but the Enterprise arrives on the scene and destroys the missiles with a fierce volley of its phasers, allowing Spock to carry through with his plan to ram the Narada.
Inside the Narada, Kirk finds Pike, alive but injured due to his earlier torture. Pike is quite surprised, but Kirk reminds him of his previous order to "come and get me", and when two Romulan soldiers walk in and find Kirk, effectively defenseless while freeing Pike from the chamber, the captain returns the favor, grabbing the gun on Kirk's belt and killing the intruders before his rescuer even realizes what happened. Scott successfully beams back Kirk, Pike, and Spock, right before the Jellyfish collides with the Narada.
The explosion of the Jellyfish ignites the entire stockpile of "red matter" on board, creating a black hole, which begins to swallow up the Narada. To Spock's surprise, Kirk offers to rescue the surviving crew, arguing that this might improve long-term relations between the Romulans and the Federation, and is thus only "logical."
Spock, mindful that Nero is the man who destroyed his planet and murdered his mother, coolly suggests that they dispense with logic in this case. Their debate is ended when Nero, belligerent to the last, says he prefers to die in agony than accept help from them. Kirk obliges and orders Sulu to fire all weapons, blowing the ship apart with phasers and photon torpedoes. 
The Narada is finally destroyed, but the gravitational pull of the black hole begins tugging on the Enterprise, keeping it from escaping, even with its engines running at warp speed. The pressure is heavily damaging the ship as Kirk orders Scott to get them out of there at all cost. Scott ejects the Enterprises multiple warp cores and detonates them near the black hole, propelling the Enterprise to safety on the resultant shockwave.
Back on Earth, the elder Spock meets with his younger counterpart, who presumed the former to be his/their father. Young Spock is confused as to why his older self didn't simply come with Kirk and explain the situation. The older Spock states that he implied there may be universe-destroying paradoxes if Kirk told him the truth so that they would have to rely on each other, thus ensuring "a friendship that will define you both, in ways you can not yet realize." 
Young Spock asks if he was making a gambit; older Spock states that he made "an act of faith" to his old friend, which he hopes that he will show again in the future. However, younger Spock expresses his decision to resign from Starfleet to help rebuild the Vulcan race; older Spock points out that he can be in two places at once. He also advises his younger self, in this case, to put aside logic and do what feels right. The older Spock then raises his hand in the familiar Vulcan salute, and, feeling it would be inappropriate to say "live long and prosper" to himself, simply wishes his younger self "good luck."
Kirk is commended by Starfleet Command, promoted to captain, and given permanent command of the Enterprise. He relieves Pike, who has been promoted to admiral and is now recovering in a wheelchair. A proud Pike shakes his successor's hand and notes that his father, too, would be very proud of Kirk. 
As the older Spock leaves to help the remaining Vulcans establish a colony, Kirk, now dressed in the gold uniform of a captain, walks on to the Enterprise bridge. After he tells McCoy to "buckle up", and receives assurances from Uhura, Sulu, Chekov, and Scott (who has barely finished talking to Kirk when he finds Keenser – now a member of his engineering staff – having climbed atop a console and orders him down) that their sections are ready to depart, the younger Spock returns to the Enterprise and asks Captain Kirk if he can be his first officer, offering to provide "character references". Kirk says it would be his honor.
As the Enterprise begins its journey, the voice of the elder Spock intones the famous motto that other starships named Enterprise have voyaged forward from:
:Space… the final frontier. These are the voyages of the starship Enterprise. Her ongoing mission: to explore strange new worlds… to seek out new lifeforms and new civilizations… to boldly go where no one has gone before.