The Other is the ostensibly undisputed villain and common foe of the protagonists of the main Girl Genius narrative. The Other is best known for instigating the Other War, during which the Other marched armies of revenants and slaver wasps across Europa, killing sparks and mentally enslaving the remaining population. The Other is currently treated as both the most dangerous and the most mysterious spark in Europa, the most legendary modern villain, much as the Heterodyne Boys that fought the Other were the most legendary modern heroes. Indeed, both the Other and the Heterodyne Boys disappeared from public awareness at the same time, causing the Other War to end about a year after it began (though Barry was last seen by Agatha, Punch, and Judy several years after the war ended).
However, the precise nature of the Other was always unknown, so "the Other" was originally little more than a synonym for what is called in another forum "the ". Until recently, virtually all details about the Other's nature and abilities were unknown, as well as many critical details of the Other's technology. (For instance, even Baron Klaus Wulfenbach, one of the strongest and most well-informed sparks in Europa, who obsessed over the Other's technology, did not realize that most revenants appear to be normal humans until almost two decades after the end of the war.)
It is now established that Lucrezia Mongfish was acting as "the Other" during the Other War, and in fact most of the main characters have come to use "the Other" as simply a synonym for Lucrezia. However, the cult of the Geisterdamen, who consider the Other their goddess, considerably predates Lucrezia, and Klaus states that the works of the Other than those produced by Lucrezia before he was banished.
This may be explained by the fact that Lucrezia Ancient God-Queens with little difficulty. Furthermore, Lucrezia has been known to inhabit multiple bodies (not all of which are under her complete control). So while the details are extremely hazy, Lucrezia Mongfish does appear to (eventually) have gained all the abilities necessary to become the Other, and then some., and one with such advanced technology that she was able to hunt down and kill many of the
One of the main loose ends concerns the Geisterdamen, who seem to, similar to the ancient God-Queens, and different in physical appearance from Lucrezia Mongfish (who has been seen to age). Some of the Geisterdamen have also Lucrezia as a fraud who simply impersonated their god. It is still unknown if the Geisterdamen originally worshipped a different God-Queen separate from Lucrezia, and, if so, how Lucrezia managed to negotiate with, impersonate, mind control, or go back in time to create that person, eventually taking control of her cult and technologies.
Another loose end relates to the Muse of Time. Lucrezia feels knowing that the Muse has been released at one point, and there are similarities between the Muse of Time, the time-traveling Lucrezia, and Von Pinn. (In particular, all three have been portrayed as cybernetic beings with either obscured or especially robotic left eyes.) The nature and significance of the connection between Lucrezia and the Muse of Time is almost completely unknown.
The Other War Edit
Main article: The Other War
Nineteen or so years prior to the beginning of the Girl Genius story, the Other came out of nowhere, attacked and effectively destroyed Castle Heterodyne, Lady Lucrezia Mongfish Heterodyne, ravaged Europa, destroyed forty-three major Sparky houses, and harried the normal citizens with slaver wasps and the resulting shambling revenants. During the attacks, accusations were thrown around at various candidates, only to see those on the list of candidates being targeted, until the moniker The Other fell into default use.
Attacks appeared to begin with the parachuting in of Hive Engines (which would create both warrior wasps as an initial strike force and slaver wasps to begin terrorizing and subjugating the population), followed by a direct strike on the target itself by high velocity kinetic weapons, and finishing with an attack using the revenants created by the Hive Engines. At the time, it was believed that all revenants were mindless "shamblers", easily detected zombie-like creatures. However, most revenants were actually normal humans in every respect, except that they had been mind-controlled to obey the Other's orders. This fact was never discovered during the war, and presumably became a major strategic advantage for the Other.
According to reports, the Heterodyne Boys did everything they could to destroy wasp infestations and foil the Other. While some people assume that the Heterodyne Boys won the war, all that can be said for certain is that one day, the devastation stopped and the Heterodyne Boys disappeared. Afterwards, Baron Klaus Wulfenbach returned from exile, suppressed the ongoing fighting, and began collecting all devices produced by the Other for disposal and/or study.
The New Other War Edit
After the Timeskip, there appears to be a new war between the Other and Gilgamesh Wulfenbach. The details are unclear, but it is known that in the early stages, Gil that she controlled many slaves on Castle Wulfenbach, only to suddenly cause those slaves to stop obeying her. (In fact, it appears that Tarvek Sturmvoraus , though he wasn't around to help implement it.) It appears that Gil , but he does possess Tarvek Sturmvoraus's , which allows him to protect his forces from becoming revenants in the first place. Furthermore, after Agatha reaches Paris, Gil containing information about the wasp-eaters, which will help him to detect revenants in the future.
That said, Gil is far from winning the war. He notes that the Queen of the Dawn (actually Zola, but believed by Gil to be an aspect of Lucrezia) has taken control of most of northern Europa, despite presenting herself not as a political leader but as a mere diva. This same Queen is believed by Grandma Terebithia to be so confident that she attacked Paris itself in the name of the Other. It's unclear how Zola is controlling the Other's forces, or whether she is simply attaching herself to a group of Lucrezia's aspects (such as the false Anevka clank), but she remains a significant geopolitical force.
Technological Supremacy and Current Status Edit
Gilgamesh Wulfenbach believes that Aaronev Wilhelm Sturmvoraus, despite obsessing over the Summoning Engine for nearly two decades, was unable to even assemble it correctly, let alone improve it. (It apparently worked on Agatha Heterodyne only because she was the daughter of Lucrezia, and thus uniquely suited to the process.)could modify the Other's work on their own. This is backed up by several examples. For instance, Prince
The only known improvement to hive engines during this time came from Gottmurg Snarlantz; while he did devise a form of wasp capable of infecting Sparks, he was only able to produce a single prototype wasp, and his research effectively destroyed his city of Passholdt. The other known improvement, the miniaturization of hive engines by Count Harken Maganox, came after the Other returned.
Gil considers these events perplexing; he does not believe that improved versions of the Other's devices could be produced without her input, but he has seen no new devices by the Other herself, which is unusual for sparks. It is notable, however, that none of Lucrezia's current copies are known to inhabit a spark, other than the version currently trapped in Agatha's mind. It is therefore possible that non-spark versions of Lucrezia (such as the one in Zola, or in the fake Anevka) are secretly running the current Other war. Such copies would presumably remember technical details about the construction of hive engines, but they would not have the spark necessary to invent new modifications to the same.
The Accused Edit
The sections below collect some of the evidence and accusations that each candidate is the Other. While it is now clear that Lucrezia Heterodyne (née Mongfish) was the Other (or at least, that she herself and all her known allies consider her to be such), there are many rumors swirling around other personalities in Europa.
Lady Lucrezia (Mongfish) Heterodyne Edit
Both Baron Wulfenbach and the Geisterdamen believe that Lady Lucrezia was the Other during the war. Baron Wulfenbach concluded that Lucrezia was the Other based, in part, on the extensive study of the Other's devices he undertook after the war. He found that the principles underlying the Other's devices were similar to those of Lucrezia Mongfish, though they were far more advanced. The similarity is not known to many besides the Baron, though Tarsus Beetle at least suspected that Lucrezia's daughter would be able to control slaver wasps. Despite other possible explanations (such as Lucrezia being forced to work for the Other), the Baron concluded that Lucrezia was the Other. It is possible that his decision was influenced by her family , the fact that she drugged and exiled him so that he wouldn't be , and the fact that she spurned him for Bill Heterodyne.
After Klaus is infected with a slaver wasp outside of Sturmhalten, he identifies Lucrezia's personality gloating about the wasp from inside Agatha's body. Lucrezia/Agatha confirms his guess. The incident likely cements his opinion that Lucrezia was the Other during the war and convinces him that Agatha is the Other now (see below). Klaus remains unaware of the "Holy Machine" and Agatha's encounter with it at Castle Sturmvoraus. (The overlay of Klaus in Gilgamesh Wulfenbach's mind, however, seems to be better informed.)
The Geisterdamen are introduced to the narrative when they take an interest in what
looks sounds like Lucrezia standing in the woods, until they determine that it is . This is the first indication of a connection between the Geisterdamen, who serve the Other, and Lucrezia. Later, High Priestess Vrin explains that she remembers when her goddess appeared in the Geisterdamen temple "in great distress", carrying the Holy Child.  After the child was taken from the Geisterdamen, the Other returned and led the Geisterdamen to the Shadow World (i.e., Europa) to fight for her in the war. Geisterdamen are seen carrying in the sewers of Sturmhalten following the death of Prince Aaronev VI (presumably their ), suggesting a further connection with Lucrezia. Agatha realizes what Vrin has been telling her means and Vrin essentially Lucrezia as the Other.
Baron Klaus Wulfenbach Edit
Klaus Wulfenbach, a major Spark from a minor house, was a fighting comrade of the Heterodyne Boys. Though absent from Europa during the Other War, he shortly thereafter to fill the power vacuum left by the destruction of the Spark houses and the disappearance of the Heterodynes to establish a vast empire. To be sure, he cleaned up the mess of leaderless wasps and revenants, but he also demanded that all the Other's devices be turned over to him. Though he claimed that this was for public safety, he is known to have studied some of these devices rather than destroying them immediately. Further, his personal passion is the study of the Spark, often by capturing and destroying Sparks. The Other was likewise interested in Sparks.
Thus, some people entertain the notion that the Baron himself is the Other. These rumors are no doubt enhanced when a giant hologram of Agatha is projected above Sturmhalten, accusing the Baron of being the Other.
T'otheron of Mars Edit
The Other was active for only about one year and few people were privy to his/her/its identity. Eighteen years later, the Other has blurred into horrifying legend. This allows Theopholous DuMedd (incidentally, nephew to Lucrezia Mongfish) to create the character T'otheron, Dragon King of Mars, that meshes with popular beliefs about the Other. Though children are amused by it, educated adults as fiction. Notably, nowhere in the main narrative does Mars appear. , however, of .
Agatha Heterodyne Edit
Even prior to her encounter with the "Holy Machine", Agatha displays some ability to command the Other's servants. Aboard Castle Wulfenbach, she tells Mr. Rovainen to ' Rovainen, apparently believing that he has received an order from the Other, in one of the labs. In the course of battling the hive engine with Gilgamesh Wulfenbach, Agatha discovers that the warrior wasps defer to her command voice.
While it is unclear how much Klaus Wulfenbach knows about this chain of events, it's unlikely that he would be reassured by any of it. He apparently knows that Lucrezia is connected to some kind of time travel technology, and fears that Agatha may be the "true" other, who simply manipulated the Lucrezia in the past into acting as such.
The late Tarsus Beetle had apparently been aware of Agatha's command voice. He had acquired a hive engine and was apparently preparing to put it into service, perhaps using Agatha to control it. What Beetle intended to do with the engine is unclear, though he certainly wanted to throw off the Wulfenbach yoke.
In Sturmhalten, Agatha commands audience members to kneel and Anevka uses a copy of Agatha's voice to very nearly control Vrin (even though she knew at the time that Agatha was distinct from her mistress). It has been suggested that those revenants who hear Agatha's command voice first are , and will preferentially follow her rather than other entities with a similar command voice.
Zola/The Queen of the Dawn Edit
In Castle Heterodyne, Zola convinces the Other in Agatha to copy the Other personality into herself as well. Having been mentally prepared ahead of time for this very possibility, Zola is able to control the personality and access (most) of its memories without any external help such as Agatha's locket. Zola eventually ends up in the Great Hospital where she meets the Other-copy in Anevka's clank. At this point, she presents herself as if the Other personality is fully in charge, but given that Zola's previously mentioned abilities, her training as an actress and her talent for general duplicitousness, it is more likely that she is fully in charge and taking advantage of the situation rather than herself controlled.
The Queen of the Dawn, Zola's new identity, at the Paris costume party. Her ability to rapidly unite numerous squabbling European kingdoms had convinced Gilgamesh Wulfenbach that she . She is perhaps unique in directing the war on behalf of the Other, without quite being a version of Lucrezia herself. She has effectively "inherited" the Other's knowledge and powers by trapping a version of Lucrezia within her own mind.
Possibly relevant outside information Edit
The Other is an important concept in continental philosophy. (The term "continental philosophy" itself "was first widely used by English-speaking philosophers to describe university courses in the 1970s [as a name for] phenomenology, existentialism, structuralism, and post-structuralism", etc.) A vague caricature of the idea is: The Other is the (innocent) person whom I make into an enemy in order to improve my Self. Therefore, the fact that the Big Bad in Girl Genius is named “the Other” is another clue that said Big Bad is not a traditional enemy such as T'Otheron of Mars, &c. but in fact an ephemeron.