In Jiangcheng, seventeen-year-old high school student Ye Xiaotian lives an utterly ordinary life: helping Uncle Wang at his noodle shop, getting dragged into skipping class by his buddy Ma Teng, and just trying to pass his exams.
No one knows that his bloodline has been sealed since childhood. And no one knows that the man in the black raincoat who broke into the noodle shop one night and brought Uncle Wang down was only the beginning of his troubles.
To stay alive and protect the people he cares about, Ye Xiaotian is forced to join a mysterious research organization, where he becomes its lowest-ranked D-class test subject. His evaluation reads: low research value, low threat level, safe and harmless.
The organization thinks it has picked up a good-for-nothing, and Ye Xiaotian is happy to play the coward.
That is, until he beats the first black raincoat senseless with his bare hands, until an "X Project" appears in his files, and until his rescuer puts an old jade pendant in his hand and says, "Look into the clues your father left behind."
There's something not quite right about this D-class.
He wants to keep a low profile, but his power won't let him. As his bloodline is unsealed layer by layer, the truth gradually emerges: the hidden hand that sealed him, the erased Ye family, and the monsters lurking in Jiangcheng's shadows are all closing in on him.
Ye Xiaotian can only keep pretending to be an ordinary high school student while putting every bit of trouble that comes knocking back in its place.
D-class or S-class?
That's for him to decide.
