Once upon a time there was a world called Winchester that was filled with magic. Despite being populated with creatures such as unicorns, dragons, sprites, mermaids, ghouls and witches, no one had seen fairies in years and now they only existed in bedtime stories.
Winchester was the home of two brothers called Sam and Dean. They were as close as brothers could be in between the bickering, the rows and pranks. They spent their time fixing up fairy stories as no one else seemed to care if the princess met the prince, whether the witch was stopped or the curse was broken. So they did the job instead. Sometimes it meant giving someone a shove in the right direction, sometimes it meant shooting a wolf with a silver tipped arrow and sometimes it meant stabbing a witch in the heart. Sometimes they got thanked, rarely they got paid and they travelled from town to town staying in shabby inns. It was usually someone else's sunset while they drove off into the dark.
Everything they owned they took with them in their old cart pulled by Impy their black mare. She was old but Dean had spent years looking after her, cleaning up wounds, nursing lamenesses and treating colics. Sam could drive if he had to but it was Dean she would canter over to if they let her off to graze in a nearby meadow, it was Dean who rode her galloping into the hills to let off steam and escape from the world.
When they were children their mother used to tell them fairy stories and other myths and legends by the fire at home. Dean had laughed while Sam listened starry eyed. Now Dean deep down wished it was true. Wished he could be the hero in someone's story, wished someone cared about his happy ending while he helped everyone else with theirs. Wished that he wasn't terrified that Sam was supposed to be villain in a story where he was supposed to be the hero.
All because a demon cursed little Sammy and both their parents were dead trying to protect him.
So it was left to Sam and Dean to carry on protecting good people from the bad people in the world. Which also meant it was left to Dean to look after Sam.
Then one night everything changed.
Sam was out on this particular evening and Dean was waiting in their room in the inn drinking out of an old chipped flask. Then with a flash of glowing sparkly light a fairy appeared standing in the middle of the room. Or at least Dean assumed it was a fairy. What else would be that small and have gossamer wings that glimmered faintly in the candlelight? He wore a faded brown coat and had a crown of blue cornflowers that was lopsided and half falling off. He stared at Dean unflinchingly with bright blue eyes as he flew into the air towards Dean.
Could it be a demon in disguise? Dean was pretty sure they didn't have wings. And he had passed all the traps he had made to get in here. The room was covered in various cages with created levers and baits. Honey, milk, dandilions, salt, various poisons and warding symbols but none of these worked. Clearly it was something else. In a last ditch attempt he shot it with a silver tipped arrow with his enchanted bow. To his horror the fairy does not even flinch, the arrow quivering in his chest.
"What are you?"
The fairy reaches down and drops what Dean can only think is fairy dust and the arrow disappears in a cloud of green sparkles.
"I am Castiel, I am a fairy, I saved you when you died trying to save Sam from the demon,"
His deep musical voice takes dean by surprise but so does hearing that he was supposed to have died. He was pretty sure he would have remembered that.
"I don't remember dying and I don't believe in fairies. Since when did fairies wear trench coats? And your flowers are falling off," Dead said accusingly because there was something not quite right about this picture, fairies shouldn't be this intense and still be covered in flowers and use fairy dust.
"Dean, how can you say that? Don't you deal in fairy stories every day?"
The little fairy flew upwards presumably so he could glare at Dean at head height.
"We have vitally important work for you to do," he said and tossed some fairy dust into Dean's face.
Dean sneezed.