Le'an's little mouth moved again, as if she wanted to say something, but in the end she just hummed softly, rolled over, lay flat on her stomach, and continued to sleep.

Chen Hao slowly raised his hand and touched Susan's hair. Strands of her hair brushed against his palm, tickling him slightly.

The room was quiet, with only the faint echo of Carl's laptop closing on the desk. Nana's indicator light was still on, its pace slightly faster than before, as if restarting from a slow start.

“That ‘Dad’ just now,” Chen Hao suddenly spoke, his voice not loud, but it brought everyone back to reality, “made me feel that all the bad luck we’ve had in the past was worth it.”

Susan opened her eyes, didn't say anything, but just leaned her head more firmly against his shoulder.

Carl looked up at Chen Hao, then back towards the crib. He remained seated, but his hand loosened its grip on the pen cap.

“I’m thinking,” Chen Hao continued, “I can’t keep dwelling on those old grievances. I’m back, I’ve survived, and my son can even call out to me now. I can’t just lie on the sofa watching short videos all day and waste my time.”

"You used to refuse to even make breakfast," Susan chuckled. "And now you're saying you want to fight for the progress of humanity?"

“That’s different.” Chen Hao sat up straighter. “I was really lazy before, but now I’m motivated. The data, ecological samples, climate records, and the things stored in Nana’s mind are all readily available. Earth is currently lacking resources, new energy sources, and technologies to adapt to extreme environments—the things we have can help.”

Carl nodded slowly: "The existing data has been processed at a rate of 63%. There are still 472 unanalyzed samples. If the research is carried out systematically, at least nine usable technical solutions can be produced within three years."

“Look,” Chen Hao slapped his thigh, “even Karl supports me. I don’t want to be a scientist; I want to turn what we know into something useful. Even if it only helps one person avoid going hungry, it’s a life well-lived.”

Susan looked at him, and her eyes changed. It wasn't surprise, nor doubt, but a kind of acceptance that she herself didn't realize.

“I hope Le’an won’t have to go through what we did in the future,” she said. “He won’t have to forage for food in the poison ivy forest, or stay up all night guarding the fire for fear of wild animals. But if he encounters difficulties, he can be like you, even though he’s terrified, he can still keep going.”

“I also taught him,” Carl said. “How to observe the wind direction to judge the weather, how to fix machines with the simplest tools. I also taught him to laugh when he heard jokes, even if he didn’t understand them.”

Nana's projector suddenly lit up, but there was no image displayed, only a scrolling stream of data. A few seconds later, a line of text stopped in mid-air:

[Family Future Growth Model - Initial Version Developed]

“Based on the current frequency of emotional interaction, physiological health indicators, and the stability of member collaboration,” Nana said calmly, “it is predicted that within the next ten years, the overall resilience of families will increase by 87%, and the happiness index will continue to rise. The success rate of responding to major crises will increase from 61% to 94%.”

"Your calculations are quite accurate," Chen Hao laughed. "So tell me, can I stick with scientific research? And not give up halfway through?"

“Historical behavior analysis shows that you have a 73% probability of abandoning the task,” Nana said. “But since Le’an was born, your goal-setting consistency has increased. Current completion rate estimate: 58%, with an upward trend.”

"Only 50%?" Chen Hao grinned. "Then you wait and see, I'm going to make this a success this time."

“You need an assistant,” Susan said. “I don’t understand technology, but I can help you organize data, write reports, and keep an eye on you to make sure you don’t slack off and sleep in.”

“The team is still there,” Carl said.

“The database module has been updated,” Nana said. “Named: Future Research Proposal. Access granted.”

Chen Hao stood up and walked to the window. It was almost dawn, but it was still dark outside. He quickly pulled back the curtains. A thin mist covered the glass, reflecting a pale white light in the morning glow.

He glanced back at Le'an. The child was sleeping soundly, his face buried in the pillow, one leg still sticking up, as if kicking in his sleep.

“During those years on the planet,” he said, “all I thought about was going home. Having a hot meal, a hot bath, and seeing familiar faces. Now I have all of that. But now I have a new thought—I don’t want to just hold onto these good days.”

"I want more people to have days like this."

Susan stood up and walked to his side. She placed her hand on his arm, lightly but steadily.

“Then let’s do it,” she said. “We’re all here.”

Carl stood up as well. He didn't speak, but simply reopened his notebook, turned to a blank page, and wrote the first line:

Project Code Name: Return Journey

Nana's projection switched, and a star map appeared on the wall, marked with the coordinates of the planet they had landed on. A dotted line extended from there, pointing towards Earth, and then branched outwards into multiple branches.

“Feasibility study directions are suggested,” Nana said, “including agricultural transplantation in extreme environments, low-energy-consumption energy cycle systems, and cross-species nutrient chain reconstruction.”

"Just hearing about it gives me a headache," Chen Hao said, scratching his head. "But I can learn it. At worst, I'll start by learning to read. Anyway, I'm never afraid of retaking exams."

"You've even managed to become an alien," Susan laughed. "What's a few technical terms to you?"

“Exactly.” Chen Hao puffed out his chest. “I used to be unable to memorize texts, but now I can understand half of what Nana is saying about quantum entanglement. I’ve made great progress.”

“The actual comprehension rate was 23%,” Nana added.

"Shut up," Chen Hao waved his hand. "Don't sabotage me."

Karl's lips twitched, almost as if he were smiling.

The three stood by the window, watching the sky gradually brighten outside. No one had turned on the lights inside, but the light was enough to make each other's faces clear.

Le'an turned over in her dream, grabbed the blanket with her little hand, and then let go.

“When he can walk,” Susan suddenly said, “I will take him to the park. In spring, when the grass is just growing and the flowers are blooming, he will walk unsteadily, but he won’t be afraid of falling because I will be there to support him.”

“I taught him to recognize the stars,” Chen Hao said. “I told him which one was the planet we’ve lived on. Even though we can’t see it with the naked eye, I know it’s there.”

“I will record every step of his growth,” Carl said. “Not just the data, but also his first laugh, his first fall and getting back up, and his first time expressing his thoughts.”

“All content will be archived synchronously,” Nana said. “Name: Family Memories, Volume 3. Access Permission: Open to all.”

Chen Hao glanced back at the crib, then turned back and took Susan's hand.

“I don’t want to be a hero,” he said. “I just want to be a useful person. Someone my son won’t feel ashamed to talk about when he grows up.”

“He’s already proud of you,” Susan said.

“I’ll ask him when he can talk,” Chen Hao laughed. “If he says ‘My dad is a complete waste,’ I’ll go back to Mars and start over.”

“We can’t go back,” Carl said. “The spaceship has run out of fuel.”

"Then I'll just grow vegetables at home," Chen Hao shrugged. "Anyway, I'm good at lying around."

Nana's indicator light flashed, as if she were smiling.

Susan leaned on Chen Hao's shoulder and whispered, "As long as you're here, home is home."

Carl closed his notebook and stood by the crib for a while. He didn't touch the baby, but just watched quietly.

Nana's projection slowly retracted, leaving the last line of text hanging in the air:

A Promising Future

Chen Hao walked to Le'an's bedside, squatted down, and looked at the little face. He stretched out a finger and gently touched the child's palm.

Le'an's fingers twitched, grasping his fingertips.