This is the innate drive of human civilization, rooted deep in our hearts, never dissipating.
The more than 86,000 volunteers were like the primitive humans who first picked up a wooden stick to fight against a beast in ancient times.
And also like the first humans who conquered their fear and rushed to the edge of a blazing forest to retrieve a flaming stick.
With the constant efforts of Harrison Clark, humanity finally took their first step out of the Solar System 2500 years ago, but it was also their last step.
At the beginning of 2500, a medium-sized unmanned spacecraft heading in another direction disappeared without a trace at a position two light-years away from the Solar System.
The Solar System Barrier had appeared again without warning.
Over the next year, seven more aircraft and detectors suffered the same fate.
The leaders of various countries realized the seriousness of the situation.
Mankind was locked in by an unknown civilization.
