A novelization of the first major StoryArc of the award-winning webcomic series ''Webcomic/GirlGenius'', released in Jan 2011. It follows the webcomic ''very'' closely, often having a distinct 1:1 mapping between panel and paragraph, but it does have a few interesting departures.

''Agatha H. and the Airship City'' is a gaslamp fantasy adventure starring Agatha Clay. She is a simple student at Transylvania Polygnostic University who gets caught up in the arrival of Baron Klaus Wolfenbach, the iron-fisted ruler of most of Europa. She also seems to have ties to the heroic Heterodyne Boys, who vanished years ago.

* AdaptationExpansion: Not much, but there's a number of small added details and background info. See also the EarlyBirdCameo.
* EarlyBirdCameo: The prologue is set 16 years before the main story starts and focuses on Bill and Barry Heterodyne. Both characters have only been seen in flashbacks and stories in the web comic.
* FunnyBackgroundEvent: Wooster and Zoing's fight.
* FunetikAksent: The Jäger/Mechanicsburg accent.
* ItTastesLikeFeet: Sleipneir's favorite cheese, which no one else can stand.
* MilitaryMoonshiner: Moloch
* {{Novelization}}: It's the novelization of the webcomic that started out as a regular print comic. This may surprise some readers who were led to expect more of a ''spinoff'' and instead got a very direct prose adaptation.
* ObfuscatingStupidity: The Jägers, constantly.
* OutsideContextVillain: The Other, when it first arrived. This is how it got its name, because it killed all of the other people that it could have possibly been.
* SecretLegacy: At the end of the book Agatha learns that she is the daughter of Bill and Lucrezia Heterodyne and heir to one of the most powerful of Spark dynasties.
* SensoryOverload: Agatha suffers a mild version of this during the first week after she loses her locket. This implies that her locket didn’t just suppress her Spark but her other senses as well.
** [[FridgeBrilliance Which explains her clumsiness in the main comic - as seen in flashback by Merlot.]]
* ShellShockedVeteran: From the description of him in the prologue this is what Bill Heterodyne has become after the destruction of his home, death of his son, disappearance of his wife, and three years of fighting the Other.
* WorldHalfFull: It's made evident in the {{Fictional Document}}s at the beginning of each chapter.
* YouGetMeCoffee: One of the added bits. Right after the Baron walks off alone in Beetleburg (to show he can), the Jägermonster in charge tells two of his Jägers "Go get me coffee, from that shop on the other side of town, and don't let him see you!" This is his roundabout way of giving the Baron an armed guard - without ''appearing'' to give him an armed guard. Who says the Jägers aren't schmott?