Cheng Xin sipped the tea quietly. She closed her eyes to concentrate on the taste. The clear bitterness seemed to suffuse her body, as though she had drunk cold starlight. She drank slowly, but finally, she was done.
Cheng Xin and Luo Ji got up to say farewell for the last time. Sophon accompanied them all the way up onto the branch. They saw that the white clouds generated by Sophon’s house had disappeared for the first time in memory. Below them, the sea of expectant people still waited in silence.
“Before we say good-bye, I’m going to finish my last mission. It’s a message.” Sophon bowed deeply to both of them. Then she straightened up and looked at Cheng Xin.
“Yun Tianming would like to see you.”
Near the beginning of the Crisis Era, before the Great Ravine had extinguished humanity’s enthusiasm, the nations of the Earth had banded together and accomplished a series of great deeds for the defense of the Solar System. These gigantic engineering projects had all reached or breached the limits of the most advanced technology of the time. Some of them, such as the space elevator, the test of the stellar-class nuclear bombs on Mercury, the breakthroughs in controlled nuclear fusion, and so on, had been recorded by history. These projects built a solid foundation for the technological leap after the Great Ravine.
But the Staircase Project wasn’t one of them; it had been forgotten even before the Great Ravine. In the eyes of historians, the Staircase Project was a typical result of the ill-thought-out impulsiveness that marked the beginning of the Crisis Era, a hastily conducted, poorly planned adventure. In addition to the complete failure to accomplish its objectives, it left nothing of technological value. The space technology that eventually developed took a completely different direction.
No one could have predicted that nearly three centuries later, the Staircase Project would bring a ray of hope to an Earth mired in despair.
It would probably forever remain a mystery how the Trisolarans managed to intercept and capture the probe carrying Yun Tianming’s brain.
One of the cables holding the sail to the Staircase probe had broken near the orbit of Jupiter. The craft had deviated from its planned path, and the Earth, deprived of its flight parameters, lost it to the endless depths of space. If the Trisolarans had been able to intercept it later, they must have had its flight parameters after the cable broke; otherwise, even the advanced Trisolaran technology would have been incapable of locating such a small object in the vastness of space outside the Solar System. The most likely explanation was that the sophons had followed the Staircase Project probe, at least through its acceleration leg, to gather its final flight parameters. But it seemed unlikely that the sophons had followed the craft for the remainder of its long journey. The craft had passed through the Kuiper Belt and the Oort Cloud. In these regions, it could have decelerated or been pushed off course by interstellar dust. It appeared that none of these things happened, because Trisolarans wouldn’t have been able to get updated parameters. Thus, the successful interception of the probe required some measure of luck.
It was virtually certain that a ship from the First Trisolaran Fleet was responsible for capturing the probe—most likely the one ship that had never decelerated. At the time, it had been sent way ahead of the rest of the fleet so that it could arrive in the Solar System a century and a half before the other ships—but, due to its extremely high velocity, it couldn’t have decelerated in time, and would have had to pass straight through the Solar System. The goal of this ship was still a mystery. After the creation of dark forest deterrence, this ship, along with the rest of the First Trisolaran Fleet, had turned away from the Solar System. The Earth had never ascertained its precise flight parameters, but if it had turned in the same general direction as the rest of the First Fleet, then it was possible that it encountered the Staircase probe. Of course, even so, the two crafts were still at great distances from each other; without precise parameters for the probe’s trajectory, the Trisolaran ship couldn’t have located it.
A rough estimate—the only estimate possible given the lack of more information—would place the moment of interception between thirty and fifty years ago, but not before the Deterrence Era.
It was understandable that the Trisolaran Fleet would attempt to capture the Staircase probe. Until the very end, direct contact between the Trisolarans and humans was limited to the droplets. They would have been interested in a live human specimen.
