How did Xiaoming die?

"I investigated a case. The victim was me." The college entrance exams are over, and it's midsummer. My deskmate invites me back to our old school building for a trip down memory lane. By chance, we discover a message left behind by the victim of a school fall that had been hastily ruled closed years ago. From that day on, strange incidents begin happening around me, and I narrowly escape danger again and again. Just to stay alive, I find myself pretending, bluffing, and getting tangled up with assassins, secret agents, mercenaries, and even monsters. Then one day, I realize that the person who died all those years ago... seems to have been me.