This one goes out to everyone who has no idea what the heck is going on in this story. 

ABO stands for Alpha/Beta/Omega, also known as Alpha/Omega or simply Omegaverse, is a cross-fandom trope that utilizes a born-into 3-caste system typically centered around mating. The specifics of ABO vary greatly from fic to fic - with some containing some pretty out-there kinks. For this fic, the specifics are outlined below. If it’s not mentioned, it won’t be present.

Alphas: 30% of population - Highest status.

Often assertive, charismatic, confident leaders. Are seen as ideal partners in media, though alphas in reality may be reckless, cocky, easily angered, or violent. Characterized by varying ual anatomy, the ability to create a mating bond, and sharing heat cycles with bonded omegas. An alpha's heat is sometimes referred to as a rut.

Betas: 50% of population - Normal status.

The most typical ‘caste’ - most are akin to normal humans, with few small differences. A small population of betas (called sub-betas) experience unproductive attraction. However, this form of heat in betas seems unable to be triggered by other betas, though further research is needed to declare this with any certainty.

Omegas: 20% of population - Varying status.

Omegas are highly sought after romantically and ually. They are seen as empathetic, mild-mannered, courageous, and kind. Some omegas may be overemotional, cold, anxious, or proud. As a result of their relative rarity and prize status, they may be treated highly by alphas and betas alike, treated as trophies rather than people, or treated lowly due to dated perceptions of status roles.

Heat is a state of heightened ual (and often romantic) awareness. There are two types of heat: full heat - aka estrus, and lesser heat (or just simply heat) - aka unproductive attraction.

Unproductive Attraction: All alphas and omegas experience unproductive attraction, as well as approximately 10% of betas (called sub-betas). It is characterized by racing pulse, thoughts, and breathing, as well as a fever, flush, and increased ual attraction to the alpha and/or omega. The specific trigger for this form of heat is unclear, though it is thought to be scent and proximity based.

Estrus: Approximately 25% of omegas experience estrus. It is a trimonthly, 5-7 day long phenomenon that typically begins starting