Part of the Star trek series, this movie goes back in time to when the crew of the Starship Enterprise first meet each other at the start of their adventures together. Those familiar with the older-aged original characters of the Star Trek series will find these younger ones to be very accurate portrayals of what they might have looked like and acted like when the famous team first met up. Captain Kirk is played by Chris Pine, Spock by Zachary Quinto, Uhura by Zoë Saldana, Bones by Karl Urban, Scottie by Simon Pegg, Sulu by John Cho, and Chekov by Anton Yelchin. The arch enemy of Kirk, Kahn is played by Benedict Cumberbatch.
The crew's first mission together is to stop a volcano on a primitive planet from destroying all its inhabitants without being seen by the natives. Spock attempts to put a device in the volcano to neutralize it but his attempt fails. In order to save Spock, Captain Kirk has to violate Starship command rules, called the “Prime Directive” which do not allow direct interference with any culture, by revealing his ship to the primitive natives. Captain Kirk is relieved of his command because of this. Admiral Pike (played by Bruce Greenwood) takes over his ship.
A terrorist bomb goes off at a Starfleet secret location on earth and the leaders are all called back to Starfleet Headquarters for an emergency meeting. The guy who set off the bomb is named Harrison who we later find out is Kahn. He attacks the Starfleet Headquarters with a helicopter shooting Admiral Pike in the process. Kirk tries to stop this, takes out the helicopter, but the attacker escapes and the Admiral dies.
Kirk is allowed to command the Starship Enterprise again because he is the only one capable of doing so. He assembles all his team for the mission to hunt down the attacker who has escaped behind enemy Klingon lines. They load a bunch of long-range photon torpedoes onboard the Enterprise to be used to attack the planet where the attacker is hiding, because they cannot get close enough to it. This is because they are ready to go to war with the Klingons and this planet is in Kilingon territory. Scotty complains these torpedoes are too dangerous to have on the ship and refuses to come onboard unless they are taken off the ship. Because of Scotty's protest, and his refusal to board the ship over it, he is left behind.
As the Enterprise nears the planet Kronos, where the fugitive they seek is hiding, all engines fail and they are stranded. Kirk, Spock and Uhura use another smaller ship, they had previously confiscated, to enter the Klingon territory and land on the surface of Kronos where they are promptly attacked by the Kingons. Surprisingly is it the fugitive that comes to their rescue. He agrees to be taken prisoner when he finds out about the supposed photon torpedoes aboard the Enterprise. He reveals himself to be Khan. He tells Kirk he is part of the war plans with the Klingons and that what Kirk thinks are photon torpedoes on the ship are actually super-humans in deep hibernation sleep that are all part of Khan's crew from long ago. Another Admiral Marcus been holding them hostage so Kahn would do what the admiral wanted so the Admiral Marcus could start the war with the Klingons.
They head back to earth and Admiral Marcus attacks the Enterprise with another larger warship, disabling it, to try to force Kirk to give Khan and the other super-humans back to him. Scotty has secretly boarded this warship of Admiral Marcus. Scotty sabotages the power allowing Kirk to board and take over the warship. Kirk also brings along Kahn because Kahn knows how to operate the warship and Kirk does not. Kahn double-crosses him and takes over control.
Kahn demands the Enterprise to beam the crew of super-humans over to the warship in exchange for Kirk. Spock beams real photon torpedoes that match the fake ones to the large warship instead. When Khan thinks his crew is onboard he plans to destroy the Enterprise but the photon torpedoes destroy the warship instead which crashes to earth. Khan escapes the crash when the warship hits earth. Kirk almost sacrifices his own life from getting excessive radiation exposure when reparing what is necessary to stop the Enterprise from also crashing into earth. Spock chases Khan down and re-captures him. He knows that a transfusion of some fo Khan's blood can be used to heal Captain Kirk from the radiation poisoning to keep Kirk from dying, which he learned from a time-shifted vision of himself in the future.
Best part of story, including ending:
The actors they picked for these roles are terrific. They are wonderfully convincing as the younger versions of the Star Trek characters that are extremely well known.
Best scene in story:
The initial meeting between Kirk and Bones is a good scene, because it is easy to see how their future will be together and how their personalities will interact.
Opinion about the main character:
Kirk is both a great captain, willing to die for his crew if necessary, and a bit of an untamed renegade that is not yet as seasoned as the character would eventually become when older.