The Enterprise completed basic repairs and reinforcement at the Vulcan drydock. Although far from its peak condition, it at least ensured structural integrity and system reliability for long-distance warp travel.
The newborn Spock, after a period of recuperation and subsequent guidance from Saavik, had largely integrated his mind with his young body.
Though he occasionally showed a subtle hint of distress over his overly vigorous physiological functions and sometimes uncontrolled emotional remnants, his characteristic calm logic and profound wisdom had returned.
His very existence was a great comfort and encouragement to all the crew members.
With a touch of sadness for the past and complex feelings for the new beginning, the Enterprise finally set off again, setting a course back to Earth.
Warp travel was smooth and efficient. When the Enterprise finally dropped out of warp and entered the outer solar system, the expected homecoming welcome did not arrive.
Instead, the communication channels were filled with chaotic static and an encrypted, continuously repeating emergency directive from Starfleet Headquarters: "All units warning! Unknown alien probe approaching Earth! Its energy signature is extremely dangerous! Repeat, all units are not to approach Earth orbit! Maintain a safe distance!"
On the main viewscreen, Earth's image was magnified.
A massive, strangely shaped cylindrical probe hung in low Earth orbit, its surface glowing with an ominous energy.
Even more alarming, a peculiar energy signal was continuously emitted from the probe's end, as if an invisible giant hand was stirring Earth.
The atmosphere experienced global, violent ionization under the signal's influence, with raging lightning storms spreading through the clouds; the ocean surface evaporated with unprecedented density, and global sea levels were visibly dropping.
The entire planet was being slowly and irreversibly deconstructed.
"Scan that signal!" Kirk's voice was hoarse with tension.
Osiris' mechanical body was already connected to the science station, his crimson optical lenses flickering rapidly, fully analyzing the destructive energy pattern.
"The signal structure is extremely complex, but its core pattern is not purely destructive energy radiation... It's more like a... communication attempt," his synthesized voice carried a hint of analytical confusion.
"Communication? With whom? This kind of communication will destroy the entire Earth!" Doctor McCoy couldn't help but exclaim.
Osiris did not reply. His processing core was comparing the signal pattern with millions of known life forms in his database.
Minutes later, he reached an incredible conclusion: "The signal's core frequency and modulation method show a high degree of commonality with the vocal waveform pattern of Earth's creature, the 'humpback whale,' although its energy level has been amplified billions of times. The object this probe is attempting to communicate with is the humpback whale."
"Humpback whales?" Kirk was stunned, a chill rising up his spine. "But that's impossible... Humpback whales became extinct in the 23rd century due to human overhunting."
This cruel reality plunged the bridge into a dead silence.
A probe from a distant galaxy, having traveled countless light-years, only to communicate with a species on Earth, a species that humanity itself had already eradicated.
Now, this belated greeting was turning into a death knell of destruction.
Kirk immediately contacted Federation high command via the still-functional secondary communication link, reporting this fatal discovery.
Soon, a top-priority directive from Starfleet Headquarters was directly transmitted to Kirk: "Captain Kirk, the Enterprise is currently the only starship in the outer solar system with independent operational capability.
Headquarters orders you, at all costs, to resolve this crisis and save Earth. You are authorized to utilize all available resources."
Pressure weighed on Kirk like a mountain.
Save Earth? How to save it? Explain to a destructive probe that its friends are extinct?
Scientists were urgently summoned to the conference room, including Osiris, Spock, Carol, and all relevant experts on the Enterprise.
The discussion was intense and desperate.
Some suggested using a stronger signal to interfere, but the risk was potentially provoking the probe and accelerating Earth's destruction; others suggested attempting to destroy the probe, but its energy shield level was unknown, and a rash attack could lead to catastrophic consequences.
Time ticked by, and Earth's condition continued to worsen.
Finally, Spock's calm voice broke the deadlock. He looked at Kirk, his eyes clear and firm: "Captain, logic dictates that conventional methods have failed. The only variable lies in time itself. Humpback whales existed in the past."
"Time travel..." Kirk murmured to himself. The idea was crazy and dangerous, but among all impossibilities, it was the only one that glimmered with a faint possibility.
After meticulous calculations and risk assessments, everyone reached a conclusion: by utilizing the extreme gravitational fields of Earth and the Sun for a so-called "gravity assist," the Enterprise had a chance to tear the fabric of spacetime and open a window to the past.
The target timeframe was locked to the 20th century, when humpback whales had not yet gone extinct.
The mission objective became exceptionally clear, yet incredibly arduous: to pilot this ailing starship on an unprecedented time jump, return to Earth centuries ago, find two humpback whales, and safely bring them back to "now" to answer the probe's call.
Kirk stood in his captain's chair, his gaze sweeping over each familiar face, seeing worry, but also determination.
He did not hesitate for a moment.
"Set course for solar perihelion. Initiate all calculations required for the 'gravity assist' procedure. We," his voice echoed on the bridge with desperate courage, "are going back to the 20th century."
The Enterprise adjusted its course, like an arrow shot towards the Sun, carrying the last hope for saving Earth, rushing fearlessly towards that scorching brilliance.
—
With precise calculations and immense courage, the Enterprise successfully executed the dangerous "gravity assist" using the Sun's extreme gravitational field.
A violent sense of spacetime distortion swept through the ship. When everything stabilized again, sensors confirmed they had successfully arrived at the target era—Earth orbit in the late 20th century.
Looking down at the planet, which had not yet experienced the interstellar age and where oceans and green spaces were still vast, the core problem of the mission lay before them: how to find specific humpback whales in the vast ocean, and how to bring these two behemoths back hundreds of years into the future?
"We need a base, and a plausible identity and method for finding the whales," Kirk gave orders on the bridge. "Sulu, switch the ship to optical stealth mode and find a concealed landing spot in the San Francisco Bay Area. Scott, ensure the stealth system and life support system are foolproof during landing."
The Enterprise, like an invisible ghost, silently penetrated Earth's thin 20th-century atmosphere, finally landing smoothly in a secluded, rarely visited valley near San Francisco.