My take on how John Winchester might have explained to a young Dean about the supernatural. Dean aged seven. Sammy three.
John hesitated on the threshold.
What he was about to do meant the end of his eldest son's childhood, not that Dean had truly experienced such a thing since his mom died.
He'd been wrestling with his conscience for weeks now. The part of his soul that was pure loving father was still pleading to be heard, raging at him that if he truly loved his sons, he'd leave them somewhere safe; protected and cared for by surrogate parents.
That way they'd get to live as normal a life as they could, far from the dangerous road John had already begun to travel.
But as the days passed and John's discoveries of the parallel world of the supernatural became more and more frequent, the 'loving father' had gradually been replaced by a man whose obsession in finding his wife's killer was becoming his sole motive of existence.
On the thinly carpeted floor, his children were playing, as yet unaware of their father looming in the doorway, too engrossed in the battle waging between the red and green plastic toy soldiers to notice him.
As he watched them giggle and yell, the way kids of their age should, he was tempted to revise the decision he'd taken and leave them with others, but he understood it wasn't possible.
What he'd found out from Missouri and from his own sporadic experiences with hunting and the world of monsters, only served to confirm that what had happened to Mary was of a supernatural nature.
In John's view, that put the entire Winchester family in potential danger of dying as she had.
Nothing happens without a reason, John figured, so even if he wanted nothing more than to give his sons the life they deserved, the hunter vibes he was developing told him otherwise, insisting that if he truly loved his sons then his duty was to teach them all there was to know about the dark parallel world of the supernatural.
With a last decisive sigh, he pushed the 'loving dad' to the side and walked through the door.
"Dad," Dean smiled up in greeting. "Wanna join in? Sammy's losing the war!"
The three-year old who answered to that name glanced up, his eyes shadowed by the mop of hair that characterized him.
"No, I'm not," he huffed. "Dean's cheating."
"That's not true, squirt," his brother grinned. "Big brothers always win!"
John interrupted before the discussion between his sons deteriorated into further bickering. "Come on out to the car. Got something to show you."
He waited for Dean's acknowledging nod, then turned on his heel and exited the room.
The boy stilled. The last couple of years he'd become hypersensitive to his father's tone of voice. John had something important on his mind, something Sammy wasn't meant to hear.
"Come on, dude. It's time for milk and cookies. I gotta go see what dad wants."
"But Dean, I wanna play some more, " the child pouted, glancing up pleadingly.
He'd already learned that if he put his sad face on, his big brother would usually cave and do as Sam asked.
"We will kiddo, just as soon as I get back," Dean said smoothly, ignoring the puppy-dog eyes, lifting his little brother onto the chair and rustling up a glass of milk and some biscuits.
When Dad wanted you to go, you went!
Outside, John was waiting in the car. The passenger door lay open, an invitation for the boy to accommodate himself there.
"Close the door, Dean."
A chill pervaded his skinny seven-year old body. Whatever dad had to say, it was serious.
Panic gripped him as he tried to recall anything he might have done to put that look on his father's face, but nothing came to mind.
Whatever he'd been expecting though, it wasn't this.
"Son. You remember the night your mom died?"
The child's face blanched, the freckles standing out starkly against the pale skin.
Dad had never wanted to talk about that night, not ever! He'd always deflected any timid questions Dean had put to him, until the boy had stopped asking altogether.
Now it seemed dad had changed his mind.
"Uh-huh," he answered warily. "She died in the fire."
"Yeah... When you came into Sammy's nursery, did you see your mom?"
Dean tried to understand why his father was suddenly asking him about that night when he'd avoided any mention before.
"She was on the ceiling, " Dean replied. "I only got a glimpse before you told me to take Sammy and run outside."
"You remember that, huh?"
In an almost adult voice, Dean answered. "I'll never forget."
John lowered his eyes, needing a moment's respite before voicing the words that would define the rest of his young son's life. But he knew it couldn't be avoided, not if he wanted to give Dean the means to protect himself and his little brother.
"You know it's not normal, what happened to your mom; on the ceiling like that, don't you?" John sighed.
Dean nodded, waiting.
"Something did that to your mom, son. Something that's still out there. Someday I'm gonna find it and I'm gonna make it pay."
The boy's eyes widened at his father's words.
"What do you mean, dad?"
John laid a hand on his son's thin shoulder. "I mean, whoever did that to your mom wasn't a man."
A confused expression shadowed the young face.
He was almost tempted to say.'Was it a woman?' just to defuse the tense atmosphere that surrounded them, though he understood it wasn't what John meant at all.
"Dean. I know this is going to sound strange, but …... there are... things out there in the dark that aren't human. Evil beings that stay hidden only to reveal themselves now and then to hurt people."
"You mean like monsters?" Dean synthesised in the only way a seven-year old's experiences could conceive what his father had just revealed.
John tilted his head in assent. "Yeah. Like monsters."
"But... why does nobody talk about them. Does no-one else know?" The child asked confused.
"Some do. But most people don't have any idea until the day something bad happens to their dear ones."
"Like what happened to mom?"
"Just like that, Dean. It made me go looking for answers and God forbid, I found them." John confirmed.
Dean took a moment to mull over what he'd just learned before asking what to him was the most important question.
"What about Sammy?"
"He doesn't have to know. He's still a baby " John said. "But I had to let you in on the secret, son, because it's gonna be your job to look out for your little brother. You'll need to learn all about these 'monsters' so you can keep him safe in case they ever try to hurt any of us again. Thing is, I'm gonna have to leave you and Sammy on your own now and then, and I need you to be sure you can protect him. Be my right hand man."
"I understand, Dad," Dean answered, still trying to take in what he'd just heard.
He'd been looking out for Sammy since their mom died, he'd fight monsters too if it meant keeping his baby brother safe.
"I know you do, Dean. So I'm gonna teach you everything I know. How to handle a gun, a knife, how to defend yourself in a fight. Whatever you need to keep yourself safe. We're gonna stay here awhile. Sammy'll be starting nursery school soon. I'll train you up when he's not around."
John wanted to pull his son into his arms, hug him and tell him not to worry, that his dad would always be there for him. But he held back. Dean had to leave his childhood behind. John hadn't asked for this, none of them had, but he sensed that evil was lying in wait for the Winchesters and he couldn't let his love for his boys hamper the training necessary to give then the weapons they needed to protect themselves.
"Good, good. I'm glad you're taking this so well," he said to his silent son before opening the door and leaving the child to his thoughts.