Ilyan Saye, a junior conservator, is tasked with cataloguing the Blackwood Estate. However, with every completed inventory, the rooms themselves vanish, leaving only a single, haunting trace. As Ilyan and a remote provenance researcher piece together the mystery, they uncover a bitter legal dispute between the last Blackwood heir and the Hallowmere Heritage Trust. The house is not sentient; it is a mechanism of a restrictive, failing legacy. This intimate gothic mystery tracks the final days of the estate as Ilyan struggles to document the impossible, leading to a final confrontation in the Hidden Attic where the physical proof of the house's erasure—and Ilyan's own professional demise—are permanently sealed.