Harrowhark Nonagesimus is framed as the last surviving necromancer of the Ninth House line, created at terrible cost. Eighteen years earlier, Harrow's parents killed all the children of the House at once to generate the thanergy needed to conceive a necromantic heir. Harrow grows up knowing this, trained by strict great-aunts, neglected by exhausted parents, and shaped into a prodigy through solitary study and harsh practical necromancy.

As a child, Harrow becomes obsessed with the Locked Tomb, the sacred and forbidden center of the Ninth House. During a suicidal crisis, Harrow opens the door expecting death, survives, and becomes curious. Later, after learning to pass the Tomb's traps, Harrow reaches the frozen coffin and sees the Body within: a beautiful dead woman holding a sword. Harrow falls violently in love with her at first sight.

Harrow's secret visits are eventually discovered by her parents, who interpret the opened Tomb as apocalypse. Rather than face the consequences, Harrow's mother, father, and their cavalier Mortus hang themselves, leaving a noose for Harrow as well. Harrow does not die with them, because despite guilt and self-loathing, Harrow wants to live and believes she has cost too much to waste.

After the deaths, Harrow's life fractures. Harrow experiences hallucinations, disorientation, compulsions, and visions of the Body, whose presence brings peace but also causes lost time. Puberty and ritual eventually help Harrow regain some control, though Harrow remains psychologically strained and dependent on structure, prayer, face paint, and Crux's care.

Harrow then maintains the collapsing Ninth House almost alone. Harrow puppets her parents' corpses to preserve the illusion of leadership, attends deathbeds, preserves failing bodies long enough for rites, raises skeletons for labor, and watches the House age toward extinction. Harrow avoids the possibility of marrying Ortus Nigenad and rejects outside aid, because intervention from other Houses would dilute or end the Ninth's identity.

The offer to become a Lyctor appears to Harrow as the miracle needed to save Drearburh, serve God, and keep the Tomb undisturbed. Harrow takes the unready cavalier from her House, but Lyctorhood repeats the pattern of catastrophe: the cavalier gives himself to Harrow, yet Harrow cannot fully consume Ortus Nigenad's soul. Harrow is left feeling unfinished, monstrous, and trapped in a cycle of ruinous mistakes, as the chapter closes by alluding to another girl who grew up beside Harrow but had died before Harrow was born.