The Journey to Pluto
The solar system's doomsday had become inevitable. The dimensional collapse triggered by the two-dimensional foil was irreversibly spreading inward from the solar system's outer reaches, with all three-dimensional matter being permanently unfolded onto a plane upon contacting the dimensional boundary. Before this ultimate catastrophe arrived, Cheng Xin and Ai AA piloted the lightspeed ship "Halo" to the edge of the solar system — Pluto.
Pluto had always been a forgotten world in the solar system. This dwarf planet orbited approximately forty astronomical units from the sun, with surface temperatures approaching absolute zero — desolate and silent. But it was precisely these extreme environmental conditions that made Pluto an ideal preservation site — at temperatures near absolute zero, virtually no chemical reactions could occur, and materials could be preserved in an almost unchanged state for billions of years.
When Cheng Xin and Ai AA's ship landed on Pluto's surface, they did not expect to find any human traces on this cold, lifeless world. Yet they quickly discovered an entrance leading underground — this entrance opened into an astonishingly vast system of subterranean caverns. Deep within Pluto's crust, a museum stood in silence, awaiting its final visitors.
The Earth Civilization Museum
The underground caverns had been transformed into a spectacular museum, displaying the cultural essence accumulated across thousands of years of human civilization. The selection of exhibits revealed the curator's profound understanding and careful consideration of human civilization's essence:
The museum preserved humanity's most important artistic masterpieces — paintings, sculptures, musical compositions, and literary works in their originals or highest-quality reproductions. Van Gogh's "Starry Night" hung quietly on Pluto's rock walls, Leonardo da Vinci's manuscripts were sealed in temperature-controlled containers, and Beethoven's symphonic scores were engraved on durable metal plates. These works represented the pinnacle of human creativity, the brightest spiritual treasures of Earth civilization.
Beyond artworks, the museum preserved extensive scientific materials — from ancient astronomical star charts to core papers of modern physics, from the earliest mathematical derivations to the complete theoretical framework of quantum mechanics. These materials recorded humanity's entire journey of understanding the universe, from the ignorant age's gazing at stars to a technological civilization commanding nuclear fusion.
Most moving were the seemingly ordinary exhibits — an animal bone inscribed with oracle bone script, a fragment of ancient pottery, an everyday object belonging to an ordinary person. These items were not outstanding in art or science, but they recorded the details of human daily life, serving as civilization's most authentic and humble testimony. The curator seemed to be saying: civilization is not only great figures and masterworks, but also the daily lives of countless ordinary people.
The Last Guardian
In the museum's deepest recesses, Cheng Xin and Ai AA encountered someone they had not expected — Luo Ji.
The aged Luo Ji had been living alone on Pluto for a considerable period. He was no longer the demigod-like figure of his Wallfacer identity — he was simply an old man, one who had chosen to do one last thing for Earth in his own way at civilization's end. Luo Ji had planned and overseen the museum's construction, carefully selecting the most preservation-worthy items from humanity's vast cultural heritage, transporting them to Pluto and placing them in this eternal ice vault.
Luo Ji's choice was deeply meaningful. As the former Swordholder, he had spent fifty-four years of his life guarding Dark Forest deterrence; now, he spent his life's final chapter guarding human civilization's last legacy. From cosmic strategic competition to cultural preservation of civilization, Luo Ji's life trajectory traced a complete arc — he was both humanity's strategic guardian and the ultimate guardian of human culture.
Luo Ji told Cheng Xin that he had chosen to remain on Pluto. When two-dimensionalization arrived, he would be unfolded onto the two-dimensional plane alongside the museum. In that plane, Luo Ji, Van Gogh's paintings, the oracle bone inscriptions, and everything of human civilization would coexist forever within the same scroll. This was not death — at least not entirely, in Luo Ji's view. Though two-dimensionalization ended three-dimensional life, all information was theoretically preserved in the two-dimensional plane. The complete memory of human civilization would persist in the universe in another form.
The Final Farewell
The reunion of Cheng Xin and Luo Ji is one of the most moving scenes in the entire Three-Body series. Two people spanning hundreds of years of time, on the coldest planet at the solar system's edge, at the moment of civilization's impending end, held their final conversation. Luo Ji was no longer young, no longer sharp, but his eyes still held a profound attachment to civilization and a clear-eyed understanding of the universe.
Luo Ji asked Cheng Xin to take some small exhibits from the museum — if she could find a new habitat in the universe, these exhibits would become seeds for the continuation of Earth civilization in the cosmos. Cheng Xin tearfully bid farewell to Luo Ji and boarded the lightspeed ship. As the "Halo" accelerated to light speed and left Pluto, Cheng Xin looked back at the cold world being consumed by two-dimensionalization, knowing that Luo Ji and the museum he guarded were becoming part of that cosmic scroll.
The Pluto Museum was human civilization's final monument. It was not built to save civilization — in the face of the solar system's doomsday, no force could accomplish that. It was built for memory — to prove that in this universe, there once existed a world called Earth, there once lived beings called humans, who created beauty, pursued truth, and experienced love and suffering. The Pluto Museum was Earth civilization's final love letter to the universe, and Luo Ji was its last signatory.