Lu Linchuan runs a junk repair shop that’s on the verge of closing. His livestream has only two kinds of viewers: those waiting for him to break something, and those demanding their money back. Then he spends two hundred yuan on a “prop beacon” burned down to a black shell. The entire internet calls it a hoax, but when the beacon powers back on, it sends a distress signal using a military protocol that hasn’t even been devised yet: the tunnel west of the city will collapse in twenty-four hours, and the recipient is Lu Linchuan, seventeen years in the future. The livestream is promptly shut down, the equipment confiscated under the law, and he becomes a trending joke as “the scam streamer who got arrested.” Materials engineer Su Jianxing rejects his conclusions three times in a row, but the fourth experiment proves that the impossible metal remembers the direction of the force applied to it. Lu Linchuan has no System and no ready-made blueprints. All he can rely on are calipers, a soldering station, reproducible experiments, and a group of people willing to make their records of failure public. When everyone wants to seize the future, he decides to first give the present a way to verify it.
