The sky had no color anymore.
Without an atmosphere to scatter light, day and night had become obsolete concepts, replaced by an eternal darkness dotted with stars that did not twinkle.
Just static points of light—nails driven into black velvet—indifferent witnesses to a small, rogue planet.
Silas Vance adjusted his weight against the cliff face. The servomotor in his right knee whirred—a high-pitched sound of metal contracting in the cold—and failed. The exoskeleton's battery was at 3%.
"Are you still looking?" Vivian's voice came through the helmet communicator. There was static, an interference caused by the cosmic radiation now bombarding the surface without a filter.
"It's hard not to look," Silas replied. He pointed a bulky glove toward the horizon.
There it was.
The Sun.
It was no longer the golden disc that had illuminated humanity for millennia.
Now, it was just a white dot, cold and distant, shrinking with every passing second as Earth traveled into the interstellar void at 100,000 kilometers per hour.
Vivian huddled closer to him. Her suit, an old bio-research model, had stopped generating active heat ten minutes ago. Silas was transferring the remainder of his energy to her through the umbilical cable connecting their suits, but both knew it was only delaying the inevitable.
"Look at the snow, Si," she whispered.
Silas lowered his eyes to the frozen ocean below.
The water had turned to solid rock years ago. What was falling now were pale, glowing blue flakes.
The atmosphere itself.
Nitrogen and oxygen were liquefying, crystallizing, and falling upon the dead world.
That bizarre precipitation covered not only the frozen ocean but also the ruins of the old coastal monitoring station a few kilometers away.
Silas watched the twisted metal structures being gently buried by blankets of solid air.
It was a cruel irony.
The very element that had allowed life to flourish for billions of years was now returning as a geological shroud, burying the last vestiges of civilization under layers of turquoise-blue ice.
Soon, all that remained of human history on the surface would be these glimmering dunes of frozen oxygen, guarding secrets that no archaeologist would ever excavate.
"The atmosphere..." Silas murmured, but his mind continued to analyze the catastrophe, even if the scene looked like something torn from a fantasy book. "We are reaching minus two hundred degrees. The nitrogen is liquefying, Viv. The air is falling on us. It is finally the end."
Vivian trembled—not from the cold, for her nerves were already too numb for that—but from emotion.
The powerlessness of someone who can do nothing but observe the end.
For a while, both remained there in silence, accompanied only by the static hiss of the communicator.
"Do you think he's sleeping now?"
The question hung in the vacuum between them.
Silas closed his eyes.
The image of the vitrification capsule descending through the hangar toward the Earth's mantle, protected by kilometers of crust, was his only relief in that moment.
"The induction process takes twelve hours," Silas said, keeping his voice steady, hiding the lie he would carry to the grave. "He must already be in stasis. Dreaming. When he wakes up, Earth will have found a new star. Or the geothermal reactors will have built a stable underground world."
"He is going to be alone, Silas."
"He is going to be alive, Vivian." Silas turned his head, his helmet's glass touching hers with a soft clink. "And that is what matters."
"It wasn't simple for you," she retorted, her voice soft and choked with emotion. "You... the bunker needed you. They will wake up in who knows how many years and won't know how to fix the air recyclers, or any of those things you made, because the man who wrote the manual stayed behind."
Silas smiled, a sad gesture that no one could see.
"William is smart. He was always better at breaking things than I was. Maybe he'll figure out how to fix them too. I left him my access codes."
A red alert flashed on Silas's visor.
BATTERY CRITICAL. LIFE SUPPORT FAILURE IN 60 SECONDS.
The cold began to penetrate.
It wasn't a common cold; it was one that hurt the bones and made teeth feel like glass about to shatter.
The universe was reclaiming the heat that biology had stolen for so long.
Vivian took a deep breath, a ragged sound.
"Was it worth it, Si?" Her voice was failing, hypothermia setting in, bringing sleep with it. "Did we do the right thing? Trading your spot... Trading the future of humanity... for his? Staying here with me to watch the sky fall?"
Silas looked one last time at the white point they once called the Sun.
He thought of the bureaucracy, the probability calculations, the coldness of the selection committees that denied their son entry due to mild asthma.
He thought of what he did, the perfect crime, and felt no regret.
"I wouldn't trade this moment for a thousand years in a bunker," Silas said. And it was the truth. "Will is our immortality, Viv. We did our job."
Her breathing began to quicken, and finally, with difficulty, she murmured.
"I miss... him, Will."
Her breathing stopped. The biometric monitor on Silas's visor drew a flat line.
He didn't cry.
He had done that enough over the last few years. He simply held her gloved hand tighter while feeling the gritty sensation of sand in his eyes, fighting against tears that could not fall.
The sun seemed to flicker out there, or perhaps it was the final synapse of his brain failing. Darkness began to gnaw at the edges of his peripheral vision. The air grew heavy, CO2 saturating what little space remained.
"Goodbye, Sun," Silas whispered to the void.
The battery light went out.
"Live well, Will."
And immediately after, the heating system died.
There was only silence, perfect and eternal, under the light of a star that was no longer theirs.