A huge alien unmanned probe sailed towards the earth, and it constantly emitted strange radio signals: powerful signals boiled the sea water, disturbed nearby starships and caused extensive damage.At this time, Lieutenant General James Kirk and his crew returned from Vulcan Star after completing the mission to resurrect Colonel Spock, flying the Raptor ship (renamed "Boil") snatched from the Klingons, although they already knew they would face charges from the military court: they were accused of stealing the Federal Starship Enterprise and being responsible for her destruction.At this moment, Spock, who is still recovering, discovered that the alien probe was trying to establish connections with humpback whales on Earth; but unfortunately, humpback whales became extinct due to excessive hunting as early as three centuries ago.Kirk ordered the Bounty to enter a state of gravity ejection, using the sun's universal gravity to travel through time and space to the late 20th century.The starship arrived in San Francisco, California, USA in 1986, and the crew hid the starship on a lawn in Golden Gate Park.After that, they began to look for whales that can communicate with alien probes, containers that can load whales on starships, and substances that can restore energy supply to the Raptors—the energy was almost exhausted during the starship's journey through time and space.Kirk and Spock eventually received assistance from Dr. Gillian Taylor, a cetacean expert, who cared for two humpback whales at the Sausalito City Whale Society.After many difficulties—including making Taylor believe they really come from the future—the crew of the Enterprise successfully rescued two humpback whales and brought them to the future, saving the planet in time.The crew were then taken to the Federal Council and accepted numerous charges.Spock, who was not accused, also stood with the other crew members.Finally, given their recent heroic performance, all charges against the remaining defendants were dropped except for the charges against Lieutenant General Kirk.Kirk was convicted of a crime of breaking orders as a superior officer and symbolically demoted to colonel as punishment; but in recognition of his heroic conduct, he was appointed captain of the Federation Starship Enterprise-A.Dr. Taylor, who came to the 23rd century with the crew of the Enterprise, decided to join the Starfleet and become a science officer.As a side plot of the plot frame, Spock shows the gradual recovery of his memory, the human traditions he had previously obtained and accepted, and his recognition of his emotions.At the beginning of the film, he did not understand what his mother meant to ask about his “feeling”; but by the end, he was able to realize enough the importance of “feeling” to humanity and asked his father to tell his mother that he “feeling good.”