It was the last day of the year 2519.
Everyone was firmly gripping their portable gene detectors.
In each massive gathering point, the multitude of gene detection towers lit up with faint twinkling lights.
No one knew from where the enemy would come, or how it would arrive.
But everyone knew what kind of enemy they were waiting for, invisible to the naked eye but as ferocious as the devil.
The clock on the wall ticked away.
The father, dressed in a full isolation suit, focused his gaze on the monitor next to him.
On the screen were the images of two separate rooms, containing his wife and daughter who had also completed their isolation preparations.
Occasionally, the man glanced at the gene detector in his hand, and then looked at the nearby fireplace.
Behind the fireplace was a medium-sized atomic disintegration garbage recycler.
This father was pondering a question.