In Dache City, memories are taxes, commodities, and punishments.
Everyone over sixteen must pay the White Tower "one insignificant memory" each month. The memories are refined into bright paste to prolong the lives of the White-Ring nobles. Those who cannot pay are declared in arrears after three months and taken away to be "emptied," becoming hollow people who are neither alive nor dead. The Forgetters, who wipe away people's painful memories, are artisans at the very bottom of the Gray Ring.
Forgetter Xie Yi only erases; he never restores. For sixteen years, he has lived by the rule of "never looking in a mirror." Then a notice bearing the White Tower's official seal arrives at his door: erase all of his own memories in three steps.
He thinks they mean to silence him, but they are actually stripping away his identity. He thinks someone else is rewriting him, then comes to understand that he was born a "blank page," a test subject numbered "Hollow Shell One" in an old White Tower case. Even the answer to "Who am I?" was copied from someone else's ledger.
But no blade can erase the seventeen years of debts he carries: the knot his adoptive mother sewed into mulberry-bark paper as she lay dying, the half piece of candy shared in the snow hut of Group Xin, the twenty-one children sunk to the riverbed, and the father who read out the ledger in public before dying of a "sudden illness" three months later.
When everyone in the city is made to forget, he is determined to write every debt back down with his own hands.