Prologue: A Tail of Two Worlds

AN: hello loves! This story was inspired by helenluvsboo on tumblr. She asked for merman!Killian and princess!Emma and their story. It started as a one-shot and is now humongous. Let me know what you think!

Hundreds and hundreds of years ago, merpeople and humans had lived in harmony. There had camaraderie between the people of the sea and those of the land. They were trade partners of rare and valuable objects and worked to keep the seas safe and beautiful. They worked hand in hand with one another for the benefit of their people and the bond of friendship long ago forged.

Until one day the peace broke; until humans began poaching merpeople for their scales, until merpeople began drowning humans for sport, until sea and earth clashed.

–some say it was actually Zeus and Poseidon, other's say myths don't make up for the nature of people–

War raged for decades. Sailors risked their lives traversing the sea for travel and trade, fear of ships being destroyed hung in the air. Many never made it back home Merfolks could no longer break the surface without risking the fisherman's net or bite of a spear. Few survived capture. Friendships were broken and families were ripped asunder. It wasn't until two great kings settled down to create a new peace that the fighting stopped, that death's ever-present grasp released.

There would be no more humans and merpeople. There would humans or merpeople, one living deep under the crashing waves and the other above on the sand. There would be no more acknowledgement or interaction, there would only be secrecy: hiding each race's precious secrets and lives in their own element.

This arrangement worked well, the fighting ceased and the seas calmed. There was never brutality against one another again, the deep-seeded hate ran cold and was eventually forgotten. But also forgotten were the times of prosperity and true peace between the two.

Humans spoke of merpeople as a myth- the past of war long forgotten. Merpeople spoke of humans as a terror- the pain of loss never forgotten.

And the line was never crossed.

Until one day it was. Until two young royals grew tired of their sheltered lives and, longing for more, found one another. Until a merman prince and human princess met by chance and accident and created a bond that no grudge could break.

The young royals knew the risk, knew the laws they were breaking, but neither cared. For they'd found kindred spirits with one another and their friendship was worth more than an old blood feud. So they continued their secret relationship until it became something neither of them planned for, until it changed their lives completely.

Killian and Emma never intended to change the world, never meant to tilt the balance between their people. But with two such as them, with fates entwined such as theirs, it was too much to hope that their lives, and love, would be simple.