After her maternal grandfather dies, Lu Zhiyao is tricked into returning to the capital by a family letter claiming that her mother is gravely ill. When she arrives at the Lu residence, she discovers that her mother is perfectly healthy. The Lu family is about to have its property confiscated and be sent into exile. Her parents summoned her back because, as the second legitimate daughter raised in her grandfather’s home, she was never entered into the family register and could conveniently take the place of Lu Zhirou, the daughter they love. When the officials call her name, her own mother pushes her forward. From that moment on, Lu Zhiyao’s name disappears, and Lu Zhirou becomes the one listed for exile. On the three-thousand-li journey, water must be bought, medicine fought over, and even making it to the next post station means trading something away. Lu Zhiyao has no magical space and cannot conjure food. All she has is an old ledger left by her grandfather. Along the way, she collects debts, trades for passage, and sells information, lighting a black lantern at an abandoned post station. At first, all she wants is to sell a bowl of life-saving water. Later, caravans transport her goods, convicts guard her shop, miners clear her roads, and even when the northern frontier runs out of food, people wait for her black lantern to shine. Then she discovers that the convicts who supposedly “died of illness” had their deaths written in advance, and the person responsible for changing the registers is the very father whose name she has been trying to clear. Xie Heng asks her, “Are you still settling accounts for the Lu family?” Lu Zhiyao closes the ledger. “Yes. What they owe me and what they owe everyone else, not a single debt will be left unpaid.”
