Shen Yan took over the "credit knife shop" left by his grandfather. There was no living person in the shop, only a rusty knife that could sing by itself.
Until that night, the system said in his ear - "Give a knife to a dying person on credit, and you can change his life; when you put the knife away, it will be the day you repay the debt."
From then on, he would pay debts owed by the underworld to the underworld on credit.
