The seventh volume of Girl Genius begins with news of a new Heterodyne girl and her battle with the Baron at Sturmhalten. Of course, everyone expects this girl to head to Mechanicsburg next. She does, but in secret.
Once in Mechanicsburg, she briefly encounters Carson von Mekkhan, makes her way to the Castle, and gets a history lesson from Wooster. Unfortunately, her plans are interrupted by the very public, very grand arrival of a Pink Airship carrying another female Heterodyne heir.
While Gilgamesh Wulfenbach fends off assassins who are targeting his injured father Klaus Wulfenbach, Agatha builds a Coffee engine. Agatha's sparky effect on the crowd and her ability to heterodyne convince the retired seneschal to assist her. Together, they enter the Heterodyne family crypt and submit to an uncomfortable procedure to obtain information for Agatha on what she will need to do once inside the Castle. The volume ends with Agatha entering the Castle in plain sight, despite danger from the plotters backing the false Heterodyne, and despite the Castle being guarded by Wulfenbach forces with orders to keep her out, by disguising herself as a convict sentenced to Castle duty.
The colors were done by Cheyenne Wright.
This volume contains the short story "Personal Trainer."