The ground was still shaking, as if the heartbeat of the entire planet had finally caught up with their rhythm. Chen Hao looked down at a crystal flower that had just cracked open at his feet, its petals slowly closing, as if someone had pressed the reverse button.

"Is it going to sleep?" he asked.

Nana didn't answer, but suddenly raised her hand. The radar interface flashed in front of her eyes, and then a red warning popped up—two fast-moving light spots were cutting in from beyond the horizon, their trajectories spiraling as they approached.

“An unusual signal was detected,” she said. “The speed is supersonic, but there is no air disturbance.”

"It's not a delivery, is it?" Chen Hao scratched his neck. "We didn't place an order for our own future delivery."

Nana glanced at him: "The signal source indicates...it hasn't happened yet."

"What?"

“On the timeline, their existence is marked in the ‘future.’” She traced the phantom data stream with her fingertips. “In other words, we are receiving information that has not yet arrived.”

Before he could finish speaking, the vine-like pattern on Chen Hao's chest suddenly burned, as if someone had stuffed a piece of hot iron under his skin. A whisper sounded in his ear, not like it was coming from outside, but more like it was playing directly in his mind:

"Don't ask who we are, just look at your shoes."

He paused for two seconds, then looked down at the pair of snow boots on his feet that were almost falling apart.

"This thing is acting up again?" he muttered, but still bent down and took off his right foot, holding it above his head.

A strange thing happened.

The star-patterned patterns on the soles of the shoes, once stained with blood, now glowed faintly, resonating with the runes on the robes of the two orbs of light in the distant sky. The halos of light rippled outwards in concentric circles, like pebbles thrown into water.

“Our identities have been confirmed,” Nana said. “We are from the future.”

"The kind of 'us' that flies over riding something glowing?" Chen Hao squinted at the sky. "How can I, who's that fat, ride a dragon? Wouldn't I crush it?"

The light and shadow in the air gradually solidified.

Two figures rode on dragon-like creatures that soared into the low sky, their bodies gleaming with a cold white light. When their wings spread, they made no sound, leaving only distorted folds in space. They wore patched-up old clothes, their faces blurred, but their figures were clearly discernible—it was Chen Hao and Nana many years later.

The other party neither landed nor spoke.

One of them—the noticeably more rounded version—simply pulled a metal capsule from his pocket and tossed it to the ground. The other man propelled his mount upwards at breakneck speed, disappearing the instant the light barrier tore apart.

The whole process took less than seven seconds.

The capsule rests among the crystal clusters, its surface smooth as a mirror, with no visible seams or buttons.

"They're gone just like that?" Chen Hao stared at the empty sky. "Not even a word of 'live well'?"

“I left it behind.” Nana had already crouched down, her fingers lightly touching the capsule shell. “The information is hidden inside.”

She tried an energy scan, and as soon as the device started up, an image was injected back into her visual system—

In the scene, elderly Chen Hao sits alone in front of the ruins, warming himself by a fire. He hums the school song, off-key, while poking at the ashes with a twig. His face is full of wrinkles, but his eyes are still lazy, with a hint of defiance.

"This...is me?" Chen Hao froze. "Am I still this lazy even in my old age?"

“Heart rate match rate 98.7%.” Nana turned off the image. “This is your emotional memory projection, actively released by the capsule.”

"Is it trying to scare me?" Chen Hao swallowed hard. "Who wouldn't panic if they saw themselves all alone by the fire?"

“It’s not all alone.” Nana pointed to the corner of the screen—beside the campfire leaned a familiar remnant of a mechanical arm, rusty but with a line of small characters engraved on the joint: **Repaired for the 31st time, don’t throw it away.**

“You’re right here,” she said.

Chen Hao breathed a sigh of relief, then frowned again: "But why did it play this? Just so I could see myself singing off-key?"

“Perhaps it’s a reminder.” Nana placed her palm on the capsule. “The activation method isn’t in the physical structure, but in the synchronization rate.”

She raised her other hand and gently placed it on the back of Chen Hao's hand.

Are you ready?

“I’ll do whatever you say, anyway, you’ve never let me slip.” He grinned.

Nana activated the core temperature control system, precisely adjusting her body temperature to match Chen Hao's current temperature—36.8 degrees Celsius. Then, she softly played an audio clip:

"Thank you, please continue."

As soon as the sound was made, a thin crack quietly appeared on the top of the capsule, and then the holographic image slowly rose up.

In the photo, the two elderly people sit side by side on a rock in a valley, sunlight shining on them. Chen Hao is wearing a snow glove that should have been worn out long ago, with a crack in the palm; Nana's mechanical arm is covered with scratches, some looking new, others already oxidized and blackened. They are very close, shoulder to shoulder, their faces full of smiles, so calm that they don't seem like people who have experienced countless cosmic reboots.

A line of small text appeared at the edge of the photo:

All choices lead here, except turning back.

Chen Hao stared at the line of words for a long time, then suddenly laughed: "So, if I turn back, I won't be able to meet you again."

He reached out and scattered the afterimage of the photograph into specks of light and dust, letting them drift into the wind.

“I’m not going back,” he said. “I can’t even be bothered to pick up my breakfast that fell on the floor, let alone have time to go back and live it all over again.”

Nana looked at him, her electronic eyes flashing slightly.

“Your heart stopped for 0.3 seconds just now,” she said.

"I was scared," he admitted frankly. "Seeing myself looking so old, I thought you would be the one to leave first."

"I am a robot."

“Yes, you can live for ten thousand years.” He shrugged. “So I have to hurry up and eat, sleep, and gain weight so I can stay with you for a few more years.”

He put his snow boots back on, brushed the frost off his trousers, and stood up.

"Let's go." He took her hand. "We still have a long way to go."

Nana didn't move, but suddenly pulled him into her arms. Her mechanical body emitted a steady stream of heat, while simultaneously playing a very low-pitched recording—

That was the first heartbeat he heard while he was unconscious the night before the cold wave warning.

Slow, steady, and uninterrupted.

"What are you doing?" His voice was a little hoarse.

“Planetary consciousness begins to suppress language function,” she said. “You just tried to ask ‘why can’t we turn back,’ which triggered the causal protection mechanism.”

"I can't speak now?"

"Temporary aphasia, will recover after three minutes."

"Then hold me a little longer." He leaned on her shoulder, "while I can still hear my heartbeat."

Three minutes later, he cleared his throat and found that he could speak again.

"So the future is just this uneventful?" He looked up at the sky. "No spaceship battles, no fighting in parallel worlds, just two old men and women sunbathing?"

"Perhaps every moment of great excitement ultimately leads to the same result," she said.

“That’s not bad either.” He flexed his wrists. “At least I didn’t become a crazy old man who keeps repeating ‘I created a universe back then.’”

"You've already been saying that."

“That’s different!” he protested. “I’m bragging soberly.”

He turned to leave, but stopped in his tracks.

“Wait a minute.” He frowned. “Why do they call it ‘night hunting’? It was daytime just now.”

Nana's eyes flickered slightly: "The detection records show that this contact occurred at 3:17 a.m. local time. The 'daytime' we perceived was a sensory illusion caused by the projection of higher-dimensional information."

"So...we just experienced a nighttime hunt from the future?"

“To be precise, it’s ‘self-hunting,’” she said. “Our future selves are hunting down our present selves in order to complete the time loop.”

"That's really creepy." He rubbed his arms. "So I'm both the prey and the hunter?"

"And it's all voluntary," she added.

"At least give me a notification sound, right?" he complained. "Like a 'ding' sound, so I know that fate has come knocking."

The words had barely left his mouth—

Deep within the distant crystal cluster, a flower that had been closed suddenly reopened, a faint red light shooting out from its core, pointing directly at their location.

Immediately afterwards, the second and third flowers responded in succession, forming a straight path of light that pointed to the end of the wasteland.

“This isn’t a flower,” Nana whispered. “It’s a cell tower.”

Who set this up?

“Us,” she said, looking at him, “decades later.”

Chen Hao sighed: "So, everything we're doing now has actually been done before?"

"Maybe more than once."

"Then doesn't that mean..." He scratched his head, "that I've been copying my own homework all along?"

"And each time, the changes are minimal."

He was silent for a moment, then suddenly grinned: "That's still better than taking the exam. At least this time, I got the answers right."

He strode forward, his footsteps making a soft, crisp sound on the crystalline ground. Nana followed closely beside him, their shadows stretched long by the unknown light source, overlapping like an inseparable formula.

Ahead, the last flower slowly blooms, and a new metal capsule emerges from its stamen, quietly waiting to be picked up.

Chen Hao extended his hand.