Transubstantiality across Potentialities

Transubstantiality across Potentialities was a book that detailed how spells were cast during the time of ancient Netheril.

Description
Even in extremely poor condition, this valuable book of arcane lore could fetch upwards of 750 gp.

History
A single, nearly-ruined copy of the book was known to lay within the treasure vault of the Tomb of Diderius, circa the 1480s DR. That copy was somehow linked to the ghost of Ilda, one of Diderius' apprentices. If it was returned to its rightful place in the tomb's library, Ilda's spectral form would no longer be bound to Toril.

Appearances

 * Adventures
 * The Rise of Tiamat