Two days later, the Emerald dome city began entering the core territory of the darkness, approaching Onyx City—which remained within the center of the darkness as the front line for defense and research—the following day. School and all activities within the city came to a halt; the government advised all residents to stay inside their respective homes and not go out unless necessary, because the dome's simulation of the day-night cycle was turned off to save energy until reaching Onyx City, which also served as a power source for recharging.
