One of a collection of 22 books found in a special footlocker stashed inside Count Lowls‘ private study in Iris Hill.
In Chapter 89, the interior of the book was discovered to have a hollowed-out compartment, inside of which was stored a miniature staircase of ivory: the focus component for an occult ritual used to travel to the Dreamlands.
In Chapter 99, the party discovered a list of gifts for the Mad Poet written by Lowls in the margins of page 42 of the tome.
First Reference: Chapter 69
Other Notable References: Chapter 89, Chapter 99