Dust motes dance in the chapel light falling across a wedding that was never supposed to be hers. Lucia stares at the stained-glass saints and swallows the only truth her family ever taught her: she is a placeholder, a political coin minted to stabilize the dukedom, while her angelic younger sister waits in the wings for the real fairytale. The coldhearted Duke is an asset the Erwins refuse to waste on a daughter they despise — so Lucia has been starved, silenced, and scrubbed of every impulse except obedience. The official record calls her the duke's fiancée. Her parents call her a tool. Then the duke's own investigation lands on her doorstep, and the ledger he unfolds is written in bruises they thought she would never show anyone.

The engagement does not shatter. It sharpens. Lucia Erwin, hollowed-out daughter, accepts a new assignment from the man they all warned her to fear: become the knife. He gives her the resources, the training, the unwavering backing of a house that could crush hers with a single decree. She gives him her icy fury, channeled into a precise, methodical dismantling of the people who threw her away. Every wound the Erwin name ever dealt her is now a line item on an account that has come due. But the question pressing against the walls of the duke's estate is whether revenge can stay cold forever — or whether the fire she refuses to name is already warming two frozen hearts.

Also known as: The Villainess Wants Revenge on Her Toxic Parents and Is Pampered by the Cold-Hearted Duke to Whom She Is Engaged, Dokubu no Ryoukan ni Fukushuu wo Chikau Akuyaku Reijou wa Reiketsu Koushaku ni Dekiai sareru, 毒親に復讐を誓う悪役令嬢は冷血公爵に溺愛される.