WMG / Narbonic

Dave created Heaven and Hell

The rest of Narbonic doesn't have much supernatural stuff... or indeed any. Clearly, then, heaven and hell, angels and demons, must all be Science!. Where did they come from? Dave created them when he was messing with Iris's microwave. It also had a temporally-unhinged component of course, allowing him to visit earlier in the strip, and allow Caliban to haunt his bed as a child.

Dave smoked in an alternate past

There are subtle hints in early strips that Dave had a smoking habit before some kind of Timey-Wimey Ball weirdness caused it never to happen.

• Naw, Dave smoking? I can't imagine that. It's not like he ever had an oral fixation, and besides, he's so healthy!

Narbonic takes place in an alternate universe of Girl Genius.

So the "mad science gene" in Narbonic functions more or less identically to "the Spark" in Girl Genius.In Girl Genius continuity, Sparks have been appearing for millenia. In times and places without advanced technology, only the very smartest and most evil (like the early Heterodynes) amounted to anything, with the rest either being too weak to use their power or getting wiped out by superstitious normals.

Eventually families descended from the powerful Sparks became dominant and ushered in a technological revolution, leading to the world of Girl Genius. In this world extremely advanced technology is available to the elite, but mass production seems almost non-existent and most people live in a medieval-like society. Weak Sparks are able to thrive to some extent in this world, because they can stand on the shoulders of giants and use technology invented by other Sparks in their own inventions. They still tend to get exploited or killed by stronger sparks.

In the past of Narbonic, these families weren't strong enough to avoid being wiped out, so the remaining Spark bloodlines became very weak and unable to use their powers. History proceeded much the same as in our world, leading to the technological revolution and widespread industrialization and a world substantially identical to ours. Because of this progress, in the nineteenth and twentieth centuries, weak Sparks gained access to modern technology and education, and this gave them the boost they needed to become mad scientists like the weaker Sparks in Girl Genius.

This is where the Narbon family enter the picture. Descended from the illegitimate daughter of a certain Hungarian warlord, the women of the Narbon family were the strongest and smartest mad scientists, even before the industrial revolution. Unfortunately, it wasn't enough. They eventually interbred with a number of other mad scientist families to produce a genetic line almost as strong as the ancient Sparks. The Davenports, on the other hand, were never anything special, just particularly lethal in shop class. However, Dave broke through as a mad scientist while in the presence of advanced mad science. This had the effect of giving him a boost into the mental stratosphere. He's still not as smart as Helen, but he's more computer savvy and a hell of a lot more stable, as it turns out.

Mell triggers people's weirdness censor

How else do you explain how Mell graduated high-school without getting arrested? She's weird enough for her antics to be censored by "reality blindness" for most people, and the rest just assume they're going insane.

Mad genius can be "eased into"

As opposed to a full-blown Freak Out mental breakdown. Walton's disorder is stated to have a sudden onset, but Helen created Zeta while still a child and in the backstory she thinks about her "interesting ideas" she's been having for years and how they're getting harder to control as she crashes into insanity. Dave's effortless Gadgeteer Genius manifests consistently throughout the story. This suggests mad geniuses are geniuses from the very beginning, and don't have to be mad to do their thing.