At the beginning of the movie, the crew of Enterprise-A are enjoying a leisurely vacation. The newly-named Enterprise is docking at Earth because of its poor performance during the trial .Refurbishment in progress. In Yosemite National Park , Captain James Kirk faced two challenges: climbing El Capiton Mountain and getting Colonel Spock to learn to sing camping songs. Unfortunately, their vacation was interrupted by a sudden emergency mission: the crew were dispatched to the desolate Nimbas III to rescue the hostages.
A Klingon lieutenant colonel, Kla, learned about the mission of the Enterprise, and decided to chase after the Enterprise to capture and kill Kirk. His actions were not authorized by the Klingon government, and at the same time, he was only in pursuit of personal honor as a fighter.
Enterprising arrived at Nimbas III. The crew discovered that the kidnapper was an emotionally controlled Vulcan Sepok, who was also Spock’s half-brother. He kidnapped representatives of Klingon , Romulan, and Commonwealth . The purpose of Sepok kidnapping these people is to seize a starship, because the government of the three hostages must send someone to rescue them.
However, Sybock is not a villain. He uses his unique psychic abilities to help others overcome his own emotional trauma, and thus gains the trust of his comrades. The purpose of Sepok, who was able to unload the resistance of most of the crew of the Enterprise, was to pass through the large barrier of the dangerous energy area located in the center of the galaxy and visit a mysterious entity located in it. Sepok claimed that he had a foreboding of the existence of the entity, and insisted on searching for it according to his own hunch, in order to directly feel the wisdom and power of the entity. During the voyage, Sepok showed his abilities to Kirk, Spock and McCoy, who continued to oppose him, and expressed his willingness to help the three to release the pain in their hearts, but Kirk firmly believed that the pain and failure of the past was a refinement. Out of part of his personality, he successfully rejected the temptation of Sepok.
Sepok successfully led the Enterprising through a large barrier that no one had successfully traversed, and came to a mysterious planet Shakari. Kirk, Spock, and McCoy decided to assist Sybock by taking the shuttle to land together and contacting the mysterious entity. At the beginning, this entity displayed Jehovah 's solemnity. He asked the group of explorers how they came here, and when he knew the existence of the Enterprise, he asked to board the ship to "spread its power throughout the universe." But when the skeptical Kirk asked about the entity's motives, he became furious.
After realizing the evil nature of the "entity", Sepok sacrificed himself to drag the demon; but while Kirk and others were waiting for the Enterprise to be transmitted, the Enterprise was raided by the Klingon battleship that followed all the way. Fortunately, Let Spock persuade Ambassador Klingon: order Kla, who followed the Enterprise into the barrier, to rescue Kirk instead of killing him.
