Grimoires are a type of Meta-Tech invented circa 7800 CS by House N'Chear to preserve and store the Soul of a dying entity. This is done by Binding the Soul to a prepared vessel with a powerful Auric-Combination spell—classic choices for a prepared vessel include skulls and tomes, though they can take many forms.
Though the stored Soul retains its memories, it lacks the wetware of a brain to encode its memories into thought, and becomes a passive store of knowledge dissociated from any sense of a present moment. This knowledge is accessible through Auric Divination, though this takes time, energy, and skill.
While creating Grimoires is a practice few places allow, they often decorate the lairs of the wealthy and the powerful, and can be found tucked back in the nooks and crannies of any place where the number of casters is greater than the number of people keeping an eye on them.
You'll never find a Grimoire that wanted it.
Meta Technology could not have advanced without Grimoires, but they're not something discussed in polite company. Historical treatment of them ranges from morbid fascination—"what a backwards and vulgar practice"—to outright vilification—"We must burn anyone who practices this wicked magic!". Even where they are at their most revered—in tales of sacrifice and valor—there lurks the underlying sense that in becoming a Grimoire your identity is lost, soul polished smooth like a stone in the tide; until all that remains is the memory of the self rather than the action of it.
Attempts to resuscitate Grimoires back into functioning bodies have vanishing levels of success even under the best circumstances. Even resuscitated, they take years to rehabilitate, if ever, and they have a vastly altered personality. They are prone to Soul Sickness.
While the understanding behind creating a Grimoire is foundational enough for a master spellcaster to piece together on their own, the practices behind more pragmatic, merciful, commumal, or militaristic use have been reinvented and lost multiple times throughout history.
Tell us about your Grimoire!