Humans are prohibited from approaching border creatures.
In a future world where technology was once highly developed but is now in decline, human society has built high walls to expel those non-human intelligent races called "simulators" outside its borders.
Shen Ran is a patrolman of the Border Biological Management Bureau. His duty is to monitor abnormal creatures and maintain border order. His life was calm and restrained, until one morning, he picked up a silver-haired boy walking out of the depths of the foggy forest at his doorstep. The young man has a delicate face, strange words and deeds, and calls himself "Bai Min".
Out of a moment of unbearability, Shen Ran took him home, but he didn't expect that this "lost cat" was actually the beginning of a huge truth.
As their daily coexistence unfolds, Shen Ran gradually discovers that Bai Min knows nothing about human society.
When the past loss, mother's betrayal, and dusty memories deep in the foggy forest were gradually revealed, Shen Ran realized that Bai Min was not lost, but had returned.
Shen Ran began to waver in the irreconcilable opposition between humans and mimics. He wanted to know, what exactly is a "real fit"? And the person who stubbornly approaches him - is he a dangerous nightmare, or is he his only reality?
Beyond the border, the snow fell and the fog fell deep.
Destiny is slowly unfolding.
Intention: love