This is if the Enterprise was not destroyed in Search for Spock.
The Enterprise approached the Genesis planet. Admiral James T. Kirk was on the bridge, looking at the viewscreen. Then Chekov, stationed at the communications/science station, spoke, in his heavily Russian accented voice:
Chekov: According to communication reports, a exploration wessel named the USS Grissom was orbiting over Genesis just a hour or two ago. Enterprise scanners detect no Federation ship around this planet. However, it is reading a spatial distortion.
Kirk paused and then said: Sulu, what do you think the spatial distortion is?
Sulu: Perhaps a cloaking device, most likely Klingon or Romulan.
Kirk then said: Chekov, put up shields as a precautionary measure.
Chekov: Aye, sir.
Chekov immediately raised shields. He thought to himself:This automation system is working better then expected,
Scotty, in his Scottish-accented voice, said: Admiral, the automation system is designed for combat, if we need to fight a battle. The Enterprise is as ready as her crew is.
Kirk: Thanks, Mr. Scott. Divert power to phasers and torpedoes, just in case.
Scotty: Aye sir. (After four seconds, he says) Power has been diverted, Admiral.
Meanwhile, on the cloaked Klingon Bird of Prey, Kruge was pacing, looking at the viewport. A Federation ship was in front of him, perhaps to check up on the progress of the Federation's so-called "Genesis device". Kruge honestly believed it was meant for evil, not to create a planet. Kruge was smiling: two of his strongest warriors were on the planet, holding a Vulcan boy, a Vulcan woman, and some blond-haired human youth as prisoners. Kruge's first officer, Torg, then said:
Torg: My lord, our scanners have detected the Federation ship is the famed Enterprise.
Kruge breathed in excitement and said: So, the Enterprise. That ship I heard is 40 years old, commanded by Kirk, James T. Kirk. Some legendary bastard....That ship defeated us Kilngons many times, as well those Romulans. It faced many dangers in it's life. I thought it was to be decommissioned.
Torg: My lord, our spies in Starfleet report the Enterprise was stolen by Kirk to rescue a Vulcan friend of his, stranded on Genesis.
Kruge: Maybe the Vulcan boy is Kirk's old friend and first officer, Spock. That bastard Vulcan has no emotion whatsoever.
Torg: My lord, Vulcans control their emotion, but they do have it.
Kruge groaned and then said: De-cloak and prepare to fire torpedoes, only on the Enterprise's engines. I do not want the ship destroyed. I want to take her as a prize of war, one that has long alluded our species.
Torg said: My lord, that would be exposing ourselves to danger. We must open communications instead.
Kruge yelled and grabbed Torg: You will do what I say!
Torg then ordered, in Klingonese: De-cloak, as captain's orders, and prepare to fire on that Federation ship.
The Klingon gunners and navigators did as told.
On the Enterprise, Kirk and company suddenly witnessed a Klingon Bird of Prey decloaking.
Sulu, in a gasped voice, said: Sir, it's a Klingon Bird of Prey. Scanners indicate it is arming torpedoes.
Kirk barked: Red alert! (Scotty put red alert on) Prepare two torpedoes for firing on that Bird of Prey.
Scotty: Torpedoes ready, sir.
Kirk then said: Fire!
Scotty pressed the firing button. The Enterprise shot two torpedoes at the Klingon Bird of Prey. The Bird of Prey was severely damaged. Kruge's monster-dog died as a result of the second torpedo. Several of Kruge's men died or were severely injured. The first torpedo caused several internal explosions, destroying the science and damage control stations. The second torpedo disabled the Bird of Prey's engine systems and disrupted primary communications.
Kruge barked: Fire plasma disruptors!
The Bird of Prey fired plasma disruptors on the Enterprise. The disruptors hit the secondary hull and saucer section, severely damaging several decks. The impulse engines were paralyzed, while the recreation deck was almost completely destroyed. Small explosions broke out in the bridge, sending Kirk and McCoy across the room.
Kirk barked: Damage report!
Scotty said: Impulse engines down. The automation center is holding on though. Several decks have been severely damaged, including recreation and one computer core. One of our dilithium crystals have burned out!
Kirk then yelled: That Klingon bastard. Open communications. We will distract them, find out what is going on.
Chekov said: Aye sir.
On the Klingon Bird of Prey...
Torg: Sir, the Enterprise is requesting communications.
Kruge: So...they might be surrendering. Put them on screen.
Torg said: Aye, sir.
He then pressed a button on the communications station, putting them on screen. On it appeared Kirk.
Kirk said: Commander of Klingon vessel, you have violated the Organian Peace Treaty between the United Federation of Planets and the Klingon Empire. Genesis is within Federation space. Go back to your space.
Kruge said: Don't lecture me on treaties Kirk. You have data on the Genesis torpedo. I want it.
Kirk said: Give us two minutes to pull it up from our computers.
Scotty, Sulu, and Chekov all gasped, yelling: Admiral!
Kirk said, in a whisper: We are tricking the Klingons. It will give us time to fire on them. Four torpedoes and two barrages of phaser shots should destroy the Bird of Prey.
Kirk then turned around to the screen, saying: What will you give us in return?
Kruge said: I have three prisoners: a Vulcan boy, a Vulcan woman, and a young Human youth.
After Kruge said this, Kirk gasped. It was Spock, Saavik, and David! Spock was alive, although without a proper mind.
Kirk then said: Stand by to receive our transmission.
Kruge nodded, ignorantly.
Kirk then turned around and said: Now, Mr. Scott.
Scotty then did what he was told. Suddenly, the Enterprise fired two barrages of phaser fire at the Bird of Prey, which disabled the Prey's communications and turbolift systems. Kruge growled: That lying Earth bastard. He tricked me!
Before Kruge could order the firing of the Prey's weapons, the Enterprise then fired four torpedoes, one after the other. The first one disabled the Bird of Prey's weapon systems. The second destroyed her emergency control systems. The third severely damaged the bridge. The final one obliterated the Bird of Prey completely.
On the Enterprise's bridge, Kirk smiled. Scotty, Chekov, and Sulu were also happy.
Kirk: Gentlemen, our laughter has not been fully accounted for. We must rescue Spock, Saavik, and David, stranded on the planet. Scotty, can you use scanners to detect their exact locations. Once you do, me, Sulu, and Chekov will go to the transporter room, and beam down there. We will defeat those two Kilgnons there. Once we do, and after we retrieve Spock, Saavik, and David, we will beam back up.
Scotty: I have scanned it, Admiral. I know the locations of them, and I will beam you down from the automation center.
Kirk said: Thank you, Mr. Scott.
Kirk, Sulu, and Chekov then grabbed their phasers. Kirk said: Set phasers on kill.
They did so.
At once, the three men left the bridge to the transporter room. Once there, Kirk said, on his communicator, to Scotty: We are ready. Beam us down.
Scotty replied: Aye, sir. And good luck.
Scotty then pulled the initiation ring on his panel, and Kirk, Sulu, and Chekov beamed down to the planet below.
They then re-materialized behind a tree. In a area to the north of the tree, was Saavik, David, and Spock, lying on the ground, with the Klingons pointing their guns at them.
Kirk said, in a whisper: Sulu and Chekov, fire at the same time, aim only at the Klingons. Be sure not to hit Spock, Saavik, or David.
Sulu and Chekov complied to Kirk's orders. They fired their phasers at the two Klingons. One was fatally injured, the other killed.
Kirk and company went over to the three former prisoners. Kirk hugged David and said: Oh, David, you are safe. You are alright!
David, said: I missed you too, Father. But anyways, before the Klignons captured us, I detected this planet was severely unstable. I used protomatter in the Genesis matrix. Because of that, the planet will explode within hours. We must get off.
Kirk looked at his son, and then turned on his communicator, telling this to Scotty: Scotty, we were successful. Six to beam up.
Scotty, on the Enterprise, activated the transporter, beaming Kirk, Chekov, Sulu, David, Saavik, and Spock up just as Genesis started shaking. The six then re-materialized in the Enterprise's main transporter room. They rushed to the bridge.
Just as they came in, Scotty said: Sir, the planet is getting unstable. We must warp out of here.
Kirk said: Mr. Sulu, prepare warp drive. Set factor at Warp 6.
Sulu: Warp drive ready. Set to go at Warp 6.
Sulu engaged the warp drive, and the Enterprise warped away from Genesis. Two minutes after the Enterprise left the Genesis system, the Genesis planet exploded.
On the Enterprise, Kirk said: Set course to Vulcan.
Sulu: Aye, sir.
The Enterprise was on warp speed, heading towards Vulcan. Kirk was happy with excitement. By the time he and the others had killed those Klignons on the planet, the Genesis planet had caused Spock to age to about the age he originally died at. So, his body was now fully re-generated. All they needed to do now was to have Spock's spirit reunited with his body. And Spock's spirit was in the mind of Dr. McCoy.
Sulu then said this, breaking the silence: Sir, we will be at Vulcan in 45 minutes, considering our present speed.
Kirk said: Very good, Mr. Sulu. Continue present course.
Sulu: Aye, sir.
Meanwhile in sickbay, Dr. McCoy was talking to Spock, who was sleeping.
McCoy: Spock, I have your katura or whatever you call it. Now you owe me, man.
On the bridge, David was solemn. He said in a coarse voice: I failed. Genesis failed.
Saavik then said: David, it was not your fault.
David said: I wish I could believe that.
Kirk gapsed in sadness.
Another forty-five minutes passed by, as the Enterprise was nearing Vulcan on warp speed. In the meantime, Scotty reported to Admiral Kirk...
Scotty: Admiral, I fixed the battle damage sustained in the short battle with that Klingon Bird of Prey. Impluse engines and the damaged decks have been repaired.
Kirk: Thanks, Mr. Scott...Scotty.
Sulu then said: Sir, Vulcan coming into view.
Kirk: Prepare us for landing near Mt. Seleya, Mr. Sulu.
Sulu: Aye, sir.
The Enterprise then exited warp speed, and Vulcan came into view. It then came down into Vulcan's atmosphere and then landed near Mount Seleya.
Kirk said: Spock will be restored.
After landing, Scotty put all systems on full automation. The computer was then put on stand-by. Scotty, Kirk, McCoy, Chekov, Sulu, Saavik, David, and Spock (on a sickbay bed) left the Enterprise, leaving her controlled by the computer. They would come back, however.
After three hours, they came back, with a mindful Spock. Uhura, who had been on Vulcan for days waiting for them, came too. They boarded the Enterprise again. They were smiling, since the pon-tal-farr ritual had united Spock's katra (living soul) with his re-generated body, restoring his personality and memories. Scotty then put the half-automation system on line. They were going to take the Enterprise to Earth to face the consequences of their actions.
Uhura, back at her post, said: Admiral, a faint communications report is coming online, it's from the office of the President.
Kirk: Put it on screen.
Uhura: On screen, sir.
On the screen appeared a barely visible image of the President of the Federation. His image was in total despair.
President: To any ships receiving this, this is Hiram Roth, President of the United Federation of Planets. All ships receiving this, do not go to Earth. A space probe of tremendous power is draining all the electricity and power reserves on Earth stations, ships, and buildings. It is sending out a indecipherable signal, in the process affecting Earth's atmosphere and oceans. The signal is aimed at water. I have declared a planet-wide emergency. So please, save your power, and stay away...
Then, the image cut off.
Kirk: We must find a way to save them.
Uhura: I am getting a unidentified signal on the communication channels.
Kirk: Put it through.
Uhura did, and a large screech was heard. Kirk and the rest of the crew were puzzled.
Spock: This sounds similar to a sort of ancient Earth animal sound.
Kirk: It might be. The president said the signal sent out by the probe was directed at Earth's oceans. Uhura, amplify the sound on all communication channels, and convert it to what it would sound like under water.
Uhura: Amplifying and converting, Admiral.
Then, the signal amplified and then coverted, and now it came clear that it was some sort of dolphin sound.