Incoming strong-interaction space probes detected.

The white wall turned bloody red, as though the hellish magma behind it had burned through. Highest alert. A line of white text appeared against the red background, each character a terrifying scream.

Total number: 6. One is headed toward the L1 Lagrangian point between the Earth and the Sun.

Speed: 25,000 km/s. Estimated arrival time at the surface: 10 minutes.

The other 5 are headed for the Earth in a 1-2-2 formation.

Later, Earth would learn that the six droplets had been hiding just outside the fifteen-million-kilometer advance-warning zone. Three of them had relied on solar interference from the Sun to avoid detection, and the other three had disguised themselves in the orbiting space trash scattered in this region. Most of the space trash consisted of spent fuel from the early fusion reactors. Even without these measures, it would have been nearly impossible for the Earth to discover them outside the advance-warning zone because people had always assumed that the droplets were hiding in the asteroid belt, farther away.

Five floating numbers appeared next to Cheng Xin, glowing with a green light. These were holographic buttons: Pressing any of them would bring up a corresponding floating window displaying more detailed information gathered from the advance warning system sweeping the region of space within fifteen million kilometers out from the Earth. The Solar System Fleet General Staff analyzed the data and passed it on to the Swordholder.

The thunderclap that Luo Ji had been waiting for for half a century arrived within five minutes of his departure, and struck Cheng Xin.

In her subconscious, she had never truly accepted that the events facing her now were possible.

Cheng Xin didn't bother pressing any of the holographic buttons. She didn't need any more information.

Right away, she understood the profundity of her error. In the depths of her subconscious, the vision she had held of the mission of the Swordholder had always been utterly, completely wrong. To be sure, she had always planned for the worst, or at least made an effort to do so. Guided by specialists from the PDC and the fleet, she had studied the deterrence system in detail and discussed various possible scenarios with strategists. She had imagined scenarios even worse than the current one.

But she had also committed a fatal error, an error that she did not and could not have realized. The error, however, was also the very reason she had been elected to be the second Swordholder.

Average distance of incoming formation of strong-interaction space probes: approximately 14 million kilometers. The closest one is at 13.5 million kilometers. Estimated arrival time at the surface: nine minutes.

In Cheng Xin's subconscious, she was a protector, not a destroyer; she was a woman, not a warrior. She was willing to use the rest of her life to maintain the balance between the two worlds, until the Earth grew stronger and stronger with Trisolaran science, until Trisolaris grew more and more civilized with Earth culture, until one day, a voice told her: Put down that red switch and return to the surface. The world no longer needs dark forest deterrence, no longer needs a Swordholder.

When she faced that distant world as the Swordholder, Cheng Xin, unlike Luo Ji, did not feel this was a life-or-death contest. She thought of it as a game of chess. She would sit tranquilly before the chessboard, thinking of all the openings, anticipating the opponent's attacks, and devising her own responses. She was ready to spend her life playing this game.

But her opponents hadn't bothered to move any pieces on the board. Instead, they had simply lifted the chessboard and smashed it at her head.

The moment Cheng Xin accepted the red switch from Luo Ji, the six droplets had begun accelerating at maximum power toward the Earth. The enemy did not waste a single second.

Average distance of incoming formation of strong-interaction space probes: approximately 11.5 million kilometers. The closest one is at 10.5 million kilometers. Estimated arrival time at the surface: seven minutes.

Average distance of incoming formation of strong-interaction space probes: approximately 13 million kilometers. The closest one is at 12 million kilometers. Estimated arrival time at the surface: eight minutes.

Blankness.

Blankness, nothing but blankness. In addition to the white hall and the white letters, everything else around her had also turned a blank white. Cheng Xin seemed to be suspended in a milky universe, just like a bubble of milk sixteen billion light-years across. In this vast blankness, she found nothing to hold on to.

What was she supposed to do?

Average distance of incoming formation of strong-interaction space probes: approximately 10 million kilometers. The closest one is at 9 million kilometers. Estimated arrival time at the surface: six minutes.

Average distance of incoming formation of strong-interaction space probes: approximately 9 million kilometers. The closest one is at 7.5 million kilometers. Estimated arrival time at the surface: five minutes.

The blankness began to dissipate. The forty-five-kilometer-thick crust above her reasserted its presence: sedimentary time. The lowest stratum, or the layer immediately above the Deterrence Center, had probably been deposited four billion years ago. The Earth had been born only five hundred million years before that. The turbid ocean was in its infancy, and nonstop flashes of lightning struck its surface; the Sun was a fuzzy ball of light in a haze-veiled sky, casting a crimson reflection over the sea. At short intervals, other bright balls of light streaked across the sky, crashing into the sea and trailing long tails of fire; these meteor strikes caused tsunamis that propelled gigantic waves to smash onto continents still laced with rivers of lava, raising clouds of vapor generated by fire and water that dimmed the Sun…

In contrast to this hellish but magnificent sight, the turbid water brewed a microscopic tale. Here, organic molecules were born from lightning flashes and cosmic rays, and they collided, fused, broke apart again -- a long-lasting game played with building blocks for five hundred million years. Finally, a chain of organic molecules, trembling, split into two strands. The strands attracted other molecules around them until two identical copies of the original were made, and these split apart again and replicated themselves… In this game of building blocks, the probability of producing such a self-replicating chain of organic molecules was so minuscule that it was as if a tornado had picked up a pile of metallic trash and deposited it as a fully-assembled Mercedes-Benz.

Average distance of incoming formation of strong-interaction space probes: approximately 7.5 million kilometers. The closest one is at 6 million kilometers. Estimated arrival time at the surface: four minutes.

But it happened, and so, a breathtaking history of 3.5 billion years had begun.

Average distance of incoming formation of strong-interaction space probes: approximately 6 million kilometers. The closest one is at 4.5 million kilometers. Estimated arrival time at the surface: three minutes.

The Archean Eon was followed by the Proterozoic Eon, each billions of years; then the Paleozoic: the Cambrian's seventy million years, the Ordovician's sixty million years, the Silurian's forty million years, the Devonian's fifty million years, the Carboniferous's sixty-five million years, and the Permian's fifty-five million years; then the Mesozoic: the Triassic's thirty-five million years, the Jurassic's fifty-eight million years, and the Cretaceous's seventy million years; then the Cenozoic: the Tertiary's 64.5 million years and the Quaternary's 2.5 million years.

Then humanity appeared. Compared to the eons before, mankind's history was but the blink of an eye. Dynasties and eras exploded like fireworks; the bone club tossed into the air by an ape turned into a spaceship. Finally, this 3.5-billion-year-long road full of trials and tribulations stopped in front of a tiny human individual, a single person out of the one hundred billion people who had ever lived on the Earth, holding a red switch.

Everything was deathly quiet. The eyes were the most terrifying: the eyes of dinosaurs; the eyes of trilobites and ants; the eyes of birds and butterflies; the eyes of bacteria… The humans alone possessed one hundred billion pairs of eyes, equal to the number of stars in the Milky Way. Among them were the eyes of ordinary men and women, and the eyes of Da Vinci, Shakespeare, and Einstein.

Four billion years were layered on top of Cheng Xin, suffocating her. Her subconscious tried to reach the surface, to catch a breath above it. In her subconscious, the surface was teeming with life, the most prominent form being the giant reptiles, including dinosaurs. Densely, they packed the ground, all the way to the horizon. Among the dinosaurs, between their legs and under their bellies, were the mammals, including humans. Still lower, under and between countless pairs of feet, were surging black currents of water: innumerable trilobites and ants… In the sky, hundreds of billions of birds formed a dark, swirling vortex that blotted out the firmament, and giant pterodactyls could be seen among them from time to time…

That baby seemed to be back in her arms: soft, cuddly, warm, his face moist, smiling sweetly, calling her mama.

Two of the probes are headed for Asia, two others for North America. The last one is aimed at Europe.

Average distance of incoming formation of strong-interaction space probes: approximately 4.5 million kilometers. The closest one is at three million kilometers. Estimated arrival time at the surface: two minutes.

Pressing the switch would end the progress of 3.5 billion years. Everything would disappear in the eternal night of the universe, as though none of it had ever existed.

Average distance of incoming formation of strong-interaction space probes: approximately 3 million kilometers. The closest one is at 1.5 million kilometers, and it is rapidly decelerating. Estimated arrival time at the surface: one minute and thirty seconds.

"No --" Cheng Xin screamed, and threw the switch away. She watched it slide across the ground, as though watching a devil.

Strong-interaction space probes approaching lunar orbit and continuing to decelerate. Extending their trajectories suggests that their targets are the gravitational wave broadcasting stations in North America, Europe, and Asia, and Gravitational Wave Universal Broadcast System Control Station Zero. Estimated impact on the surface: thirty seconds.

Like a strand of spider silk, these final moments stretched out endlessly. But Cheng Xin did not vacillate; she had already made up her mind. This wasn't a decision born of thought, but buried deep in her genes. These genes could be traced to four billion years ago, when the decision was first made. The subsequent billions of years only strengthened it. Right or wrong, she knew she had no other choice.

A great jolt tumbled her to the ground: The droplets had penetrated the crust. She felt as though the solid rocks around her had vanished, and the Deterrence Center was on top of a giant drumhead. She closed her eyes and imagined the sight of a droplet passing through the crust like a fish swimming through water, waiting for the arrival at cosmic velocity of the perfectly smooth devil that would turn her and everything around her into molten lava.

It was good that release was at hand.

But the quaking stopped after a few violent beats, like a drummer punctuating the end of the piece.

The red light on the screen faded, replaced by the white background from before. The room seemed brighter and more open. A few lines of black text appeared:

North American gravitational wave transmitter destroyed.

European gravitational wave transmitter destroyed.

Solar radio-amplification function suppressed on all bands.

Asian gravitational wave transmitter destroyed.

Cheng Xin understood that the droplet attack on the Asian gravitational wave transmitter had caused the earthquake. That antenna was about twenty kilometers from here and was also deeply buried.

The droplets had not even bothered attacking the Swordholder.

Silence once again reigned over everything, except the faint sound of water trickling somewhere. A pipe had burst during the quake.

The black text disappeared. After some moments of blankness, a last screen of text faded in:

Gravitational wave universal broadcast system cannot be recovered. Dark forest deterrence has been terminated.