Necronomicon

The Book of the Dead, believed to be one of eight divine relics somehow central to the integrity of reality itself. Anything which touches it is cursed by (un?)death. Naming a creature and writing its name in the book dooms them to die.

Once locked in the treasure vault of Dominic Tremere, the Necronomicon was then arranged to be stolen by the medusa Pulchritudinous Euryale and traded to the ex-druid Isis Ra’ksh in exchange for a potion to restore Euryale’s humanity.

Stolen by Isis Raksh and currently pursued by the warforged R. Martine Andrews in the Deepwood.

Once in Isis’s possession, she used it to poison the Yggdrasil in a misguided effort to counter a nebulous world-destabilizing force she called the Vortex. But the Book’s evil took root within Isis, festering into the parasitic entity Zuggtmoy, before jumping to the Fae Queen. When this happened, Isis came to her senses and discarded the Necronomicon in horror at what she had done.

Kept safe in the royal vault by Tybalt, with warnings that it should not be touched due to its dangerous feedback mechanisms.

Was cleansed of its evil writings through a ritual performed by the party and Lorissa Stormseeker, though it retained some residual darkness.

Finally cleansed of all evil after Lorissa cast remove curse, though the full ritual to destroy it remained incomplete.

Elven scouts recovered the discarded Book and locked it away in the royal treasury; the SPI infiltrated the treasury and aided Sartus Morningdew in invoking a miracle, the pinnacle of mortal magic, to erase the writings in the Book, cleansing its corruption at the source.

Mentioned as having been given to the elves in a prior case.

Revealed to have been Invictus’s phylactery; when cleansed, it also cleansed Invictus, pushing his soul out and likely into a living body.

Referenced in the discussion about it being Invictus’s phylactery and why the situation won’t repeat.