The nineteenth volume of Girl Genius begins with…
The colors were done by Cheyenne Wright.
The first page of volume six of act two begins here: The Second Journey of Agatha Heterodyne.. While this volume is often referred to as the sixth volume of act two for short, it is officially the sixth book of
This volume has two pages of extras, providing a 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) each included a summary of "The Story So Far" and a humorous capsule biography of the professors which this volume omits.