Book One: Air
Chapter I: The Girl and the Lake

In Fire Nation propaganda following the genocide of the Air Nomads, several textbooks and scholarly articles describe Air Nomads as "parasitical" and "an infestation".

Parasitism, in cultural terms, is a highly subjective term: on a biological level, they can be described as either completely isolated or, in fact, reciprocally altruistic. An infestation, however, is another story.

An infestation commonly refers to the invasion or overpopulation of pests or parasites. The latter half is, again, subjective, but the propensity of humanity towards reproduction is well-documented. In fact, expanding the human gene pool is healthy for the species, provided no cultural barriers.

Air Nomads have no such reproductive suppression. In fact, around the time of Guru Laghima, Air Nomads encouraged constant interaction with other nations, in the name of spiritual harmony and understanding. The result of Guru Laghima's enlightenment and the nationalization of the Air Temples resulted in a cultural shift towards isolationism and enlightenment, but this was not enough to majorly shift the culture of the nomadic population. During and after Avatar Yangchen, airbenders still pursued consistent interaction with the outside world.

With no cultural or physical barrier, and no taboo against the matter, it only follows that airbenders intermingled with the world. This includes genetic admixture. As such, several non-nomad airbenders arose in various populations. This would not last long after the denomination of Sozin's Comet: following Fire Lord Sozin's rule, the Fire Nation treated the phenotypic expression of airbending as a disease to be purged. The worldwide population of airbenders, Air Nomads or otherwise, were reduced to a dwindling population.

This sudden pressure on population levels meant that only genes with certain characteristics would survive the purge. Although bending is commonly a recessive gene in waterbending and earthbending (although, on a higher level of genetics, alleles aren't nearly so rigid), airbending has been traditionally dominant and seen in all Air Nomads, thus providing an easy indicator for Fire Nation determinants. A change in the expression of the airbending gene had to occur for the population to continue.

But, as it often occurs in nature, survival occurs even under extreme stress, usually as a result of genetic mutation. In this case, the mutation simply made airbending recessive. In airbending populations adjacent to the Fire Nation itself, the statistically few non-bending offspring could successfully inject themselves into the Fire Nation with minimal discovery. Furthermore, their genotype did not express their phenotype; the mutation had occurred successfully, and the surviving population began to reproduce.

Luckily, the airbender genocide was only about three human generations away; a blink of an eye, genetically. The genetic code didn't have enough time to mutate into inactivity, and the recessive allele could proceed onwards. Which brings us to the first case of this proposed disease, a female offspring born as part of monozygotic septuplet in the F4 generation of our genotype of interest:

Ty Lee.

Like many diseases, it starts with a sneeze.

Usually, the sneeze itself is the main cause of spreading, usually when referring to the airborne transfer of bacteria or other malefactors. For example, the later-discovered epidemiological marvel known as pentapox. However, this sneeze was more than that. It was a phenotype.

The first thing Ty Lee felt was heightened irritation and cranial pain. She'd hit her head on the ceiling, and then her mirror fell over and shattered, and then her scrolls got strewn all over, and this phenotype was doing horrible things to her aura.

The second thing Ty Lee felt was pure, unadulterated horror.

The human crisis response is not well-documented in this world, given the physical distance and socioeconomic difference between educated scholars and those suffering tragedy. Ty Lee surmises she would like to see future research in this area: or, we can infer this, because of her frantic inner screaming of 'what do I do, oh, spirits, what do I do, I'm an airbender, I can't be an airbender, they're dead, we killed them, what do I do', et cetera.

Immediately, a servant came to check on the loud noise: it would not do for Ty Lee's parents to suffer a loss in the family this early, given the financial and political repercussions of said mortality. Quickly adapting to the situation, Ty Lee supplies faulty documentation of the matter, citing a 'backflip gone super, duper wrong', among other similar falsities. The servant works to clean the mess (Ty Lee offers to help but is rejected) before things are relatively tidy again fifteen minutes later, sans a mirror.

Once the door is closed, our subject uses a relatively healthy coping mechanism, consisting of shoving her face into a pillow and screaming to the extent of her vocal cords. Then, she falls silent and considers her options. She is a well-trained member of Fire Nation nobility, and so looks towards pragmatism in response to trauma.

Before proposing a solution, it is universally acknowledged that all obtainable knowledge of the matter should be accrued in a timely manner. Ty Lee is on summer vacation from the Royal Fire Academy for Girls, but their lessons hold well. So she does not conclude that she is the Avatar. She does not form a plan to escape the Fire Nation, or to claw her way to the Fire Sages to seek answers. Rather, she asks a question, and forms a hypothesis to test (even if unaware of the process of inquiry, herself.)

Are her sisters also airbenders?

If her sisters are airbenders, then they should respond to the same stimulus as she did.

And so Ty Lee experiments.

It should be noted that Latin names do not exist for the various organisms of this world. Firstly, because Latin does not exist, and secondly, because every flora and fauna is a hybrid abomination of two completely different organisms. Except the bear, apparently.

As such, the walnut-daisy tree will be referred to as such. It is a flower-tree with absurd amounts of pollen that erupts from its flowers during the summer. The smell is reportedly sweet and pleasant, and thus a common aroma for houses of nobility.

It is also a major allergen for the Ty family, and within forty-eight hours of Ty Lee's sudden revelation, the entire house is plagued with sneezes while the servants do their desperate best to ventilate the walls of any remaining microgametophytes.

The mass symptomatic response provides plenty of data for Ty Lee to process. To note: she feels awful about doing this. Her sisters all give her the stink-eye, especially because Ty Lee had the spare time to sew a cloth mask for herself. Her parents scold her, because she should know how allergic they all are, and they suspect foul play, and look how dishonorable and unsisterly and borderline rebellious Ty Lee is acting, how dare her. This is intensified by the fact that Ty Lee does not contradict them.

Instead, in her head, she's reviewing her results. Evidence supports her hypothesis that the other Ty sisters are not airbenders. Ty Lee makes the logical fallacy of accepting this evidence as enough fact to act upon, but given her resources, time constraints, and lack of training in the sciences, this is generally acceptable.

So, she moves onto further hypotheses. Other authors might restate this as 'Ty Lee starts getting wild ideas about her parentage, about her future, about anything and everything and if her mother had a tryst with an old, bald man in the past'.

She spends a whole week considering these hypotheses before her vacation is over and she returns to the Academy at the age of nine. The mild panic she feels is worsened when she's greeted by her best friends. Not every firebender has a mutation that allows temperatures hot enough to produce blue, after all.

As a well-known yet understudied behavioral phenomenon, firebenders rise with the sun, unaffected by time zones, seasonal changes in daylight hours, light amounts, or even the visibility of the sun itself. They are perfectly diurnal if not behaviorally modified: but this is dependent on the illusion of the sun itself rising, the edge its disk over the horizon, which itself is affected by the refraction of light around air, ironically enough. Although the visual cue of visible dawn dictates firebending diurnal waking, in actuality, the sun has "risen" a few moments beforehand: this is known as astronomical dawn.

Ty Lee, hyper-aware of her new bending abilities, rendered anxious and slightly manic by the danger surrounding her, rises at this astronomical dawn. The edge of day, when a bright orange hue paints the horizon, and the darkest night stays perfectly above it. The stars are still visible during this time, and the sun is not visible, and so the firebenders are still asleep.

At this time, she has an hour – maybe two, if she rises a bit earlier – for herself, before the day starts. Her friends are asleep, so she spends this time taking a small walk to a nearby lake, squinting her eyes to see the path in the half-dark, half-light.

The lake, subjectively, can be described as beautiful. It is called Lake Tennjin. The likeness of similar lakes around this time has been portrayed in scrolls across the four nations. A vast, dark expanse, with brushstrokes of orange reflecting the shallow waves, as the twilight sky hangs above. At this particular lake, in this particular ecosystem commonly found in the Fire Nation, schools of fireflying-salmon float near the surface, their bioluminescence visible to the naked eye.

And then they are eaten. The wild raven-eagles come out during this time to prey on the fish while they are resting, indicated by sonorous war cries of coordination in the murder-convocations. (Ty Lee always thought it unnecessarily warlike, to call a flock of such pretty birds that sort of thing.) They rise, they soar, and then they dive so deep into the water one could surmise they drowned – and then they come right back out with prey in talons.

For the first week of her early mornings, Ty Lee is too busy in thought, trying to come to terms with the new changes in her otherwise princess-adjacent life. She struggles with morality, the best a nine-year-old can. The volume of questions, hypotheses, mental experiments, and unprecedented data is too much for her undeveloped personality to process: issues of ethics, of politics, of religion and of the ultimatums of life. Of her own importance. Of her life, and her death. But she tries.

In the second week, Ty Lee looks up from the muddy shallows where she rests her feet and watches the raven-eagles. How they soar and dive and kill. How smart they are, to bait the fireflying-salmon into leaping out of the water, and then clipping the flying fish as they rise. How free they are, happy to hunt, unchained by the conventions of the Fire Nation, happy to work and eat and play and live.

In the back of her mind, her aura sours with the thought that some of these raven-eagles will die or be chained, either hunted for game or pelts, or captured by falconers to be used in the Fire Army. But she sees them, how careless they are of such facts, how they simply live until they do not, and it feels right. More than anything else in her life.

And somewhere in that second week, she stretches and goes through her katas she learns in the Academy – but begins to change them, mimicking the movements of the birds of prey. The swift cuts, the precision strikes, the flying talons all flow through her veins, unrefined, dirty, and yet as natural as a cat-deer walks from birth.

(In the quiet of dawn, as Ty Lee practices with only herself and her aura and a smile on her face, her ancestors scream and cry as their last known hope commits the greatest sin of any Air Nomad.

She does not learn to airbend from the flying bisons.

Ty Lee learns to airbend from the raven-eagles.)