An estimated thirty percent of Tier 1 residents in the Shelf are running unregistered brain-computer interfaces inherited from family members. The practice is technically illegal under Lazarus licensing agreements, which require each BCI to be registered to a single user and decommissioned upon that user's death. Enforcement is nonexistent. CorpSec has never once prosecuted a case of BCI inheritance in the Shelf. The devices are too expensive for most families to replace — a new Lazarus Tier 1 BCI costs between Φ80 and Φ400 depending on capability tier — and the used ones cost nothing except the courage to let a street clinic perform the transfer surgery.

Factory reset is supposed to wipe the device clean. It clears stored data, personal configurations, feed preferences, and communication logs. What it does not clear are the physical neural pathway adaptations that form in the BCI's substrate over years of continuous use. The device literally reshapes itself to match its host's brain. When that host dies and the device moves to a new skull, those physical formations remain. They are hardware, not software. No reset touches them.

The Shelf has a word for what happens next: ghost weight. The new user carries the residual neural habits of the previous owner. A daughter inherits her mother's BCI and finds herself reaching for masala chai her mother drank every morning — a beverage she has never tasted and does not enjoy. A fourteen-year-old boy receives his dead brother's implant and begins flinching at the sound of slamming doors. His brother was beaten by a landlord who slammed the door before every blow. The boy has no memory of this. His body remembers anyway.

Third-generation devices — grandmother to mother to granddaughter — show the most disturbing manifestations. The ghost weight layers. A granddaughter running her grandmother's BCI, passed through her mother, exhibits knowledge of locations that were demolished before she was born. She navigates to addresses that no longer exist. She recognizes faces in crowds that belong to people decades dead. She possesses fragments of skills the original owner practiced — soldering techniques, haggling strategies, the muscle-memory of lullabies sung to children who are now grandmothers themselves.

This investigation interviewed forty-seven families across six Shelf blocks who confirmed multi-generational BCI inheritance. Every single one reported ghost weight phenomena. Every single one considered it normal. When asked if the practice frightened them, a common response emerged: "She's still in there. Why would that scare me?"