The Central Plains dynasty where the story takes place built its nation on agriculture. The north has suffered drought for three years straight. Riverbeds have run dry, the snowline creeps south year by year, and well water comes up brackish and foul. Natural disasters themselves are nothing unusual. What is unusual is how they are recorded on paper: household registers in the prefectures and counties, grain ledgers in the Ministry of Revenue, the amount of grain stored along the grain routes, and relief requests from the various garrisons, all reported upward layer by layer, with each layer quietly erasing a little more. Refugees form a black line along the roads. Ditches by the roadside fill with people who have not yet frozen solid, while in some office in the capital, their corpses are merely figures crossed off a ledger. The “geography” of this book is not a map of mountains and rivers, but one of grain routes and disaster zones: which granary opens, which stretch of canal is closed, which pass lets refugees through, and which narrow pass bars them from crossing. These decisions determine whether a family reaches the south alive or falls by the wayside. The protagonist's family is killed by these invisible routes. His father falls in the snow, and his mother stuffs the last half of a flatbread into his hands before lying down in a ditch. These two deaths by starvation are not random tragedies, but the inevitable result of a system of ledgers in motion. Readers must understand from the start that natural disasters are the backdrop of this world. The true killer is the hand that draws lines on paper.