While working the night shift, city map auditor Yu Zhaolin sees a street that was demolished long ago appear on the city map at 12:17 a.m. The System orders him to delete it within fifty-nine seconds. But the last resident on that street is his younger sister, who has been missing for eight years.
When the call connects, she asks only one question: "Brother, are you going to delete me again?"
From that night on, abandoned stations start announcing arrivals again, and a closed hospital continues assigning birth addresses to the living. Behind every old name erased from the city, someone is still living, searching, or refusing to be found. Yu Zhaolin can write those names back onto the map, but the price is one of his own private memories.
When twelve cities begin erasing their old names at once, he finally realizes that the path home his sister left behind is also a door keeping a thousand cities from overlapping.
