This is a plagescrowe, the "holy book" of the plague cultists of Aratrice, it does have stories, lore, and rituals related to the deity, but it's mostly informational and has details of food sources and medicines one can make with the resources in the plague realm, useful to both priests and doctors.

It also contains maps of the plague realm to navigate, kept updated as it expands and gains new settlements by scribes, one member of the plagalatry may have a plagescrowe different from another

Notably, this book is opened sideways like a laptop or pizza box.

Some may update their plagescrowe with a focus on cataloging the culture of the Aratrice cultists, as well as recipes, dishes, or notable artworks, common sayings, and more.