In the story, they were on the way to rescue the fair maiden Miss Becky from the clutches of arch fiend Dr. Mongfish. The evil doctor, upon seeing their approach, blasted them with the ‘Hero Vaporizer’, causing them to vanish, where to the Doctor did not know (or care).
Unbeknownst to him (but beknownst to us), the pair, and their sidecar motorcycle, were transported to a seedy bar in the interdimensial city of Cynosure. Encountering a variety of bizarre men and creatures, the two heroes found themselves being threatened by one who was upset by his spilled drink and wanted their blood as a repayment. As that this was ‘indubitably’ an evil doer, they executed ‘Plan 4’ striking down the assailant, killing him to their surprise.
Talking to the barkeep, they revealed that were empowered to maintain the kharmic balance and were dutybound to defeat any evil doer, anybody who was not ‘good’, though normally the villain was simply defeated and imprisoned for a short time. When Munden casually pointed out that the entire patronage of the bar (which appeared to include the esteemed Buck Godot) could be considered ‘evil’, the brothers prepared to do battle with the suddenly well armed denizens.
The fight was prevented by the arrival of Phaeton, Lord Protector of Cynosure, who felt the presence of two 'Avatars' of good (as they were in their home dimension). He explained that they simply could not lose against evil. As that their world did not have the shades of grey present in Cynosure, they would certainly devastate the bar and probably successfully take on the entire city if allowed to continue. Using his powers as Lord Protector, he transported them home to their universe, but not before turning down their offers to 'assist him' in his duties.
As for the boys themselves, they defeated the evil Dr. Mongfish, got the girl, and enjoyed a cup of tea.
When the idea for Girl Genius was first created, Agatha was to be the descendent of these two brothers set in the near future. Eventually, the story was refined to the 'steampunk' setting it has now. In the process, the Boys themselves were changed radically in appearance and became her father and uncle.
Possibly relevant outside informationEdit
More uses of the Heterodyne Boys in Phil Foglio's work are documented by Lee K. Seitz.