The title of this volume, The Incorruptible Library, was revealed by Kaja in an update to the Kickstarter campaign for The City of Lightning: a Girl Genius Graphic Novel by Studio Foglio in late May 2017.
The sixteenth volume of Girl Genius begins with…
The colors were done by Cheyenne Wright.
The first page of volume three of act two begins here: The Second Journey of Agatha Heterodyne and the sixteenth volume overall.. While this volume is often referred to as the third volume of act two for short, it is officially the third book of
This volume has two pages of extras, providing a fairly extensive cast list with capsule descriptions of the characters along with definitions of some terms used in the story, at the beginning of the book.
Presumably, a cast list has been included in this volume, although one wasn't present in volumes in the First Journey, because books in the Second Journey are supposed to be a good starting point for new readers. The previous volumes (The First Journey of Agatha Heterodyne, books 1–13) did each include a summary of "The Story So Far" and a humorous capsule biography of the professors, which this volume omits.