Round cheeks flushed in the chill of the night, baby Dean reached a chubby, grasping hand towards the sky and burbled, "Ca," John and Mary, not yet knowing any better, wrote it off as infantile babbling and cooed back at him meaninglessly. Their faces distracted him from trying to grab at the tiny lights overhead, and then they reached the fairgrounds there were people, colors, and sounds abound to keep him occupied.
An hour or so later, worn down by the excitement and stimuli, Dean slept in the cradle of John's arm for their walk back to the parking lot. It was late for such a young boy, and he didn't stir when they buckled him into the car seat or when they took him out. He only blinked sleepily awake once, when they tucked him into his crib, and that lasted just long enough for a yawn. He was out again like a light a moment later.
When he waved his arms happily at the sight of his mom and exclaimed, "Ma!" the next day, they called that his first word and Mary couldn't have been happier.
None of the Winchesters ever remembered his real first word—Dean was too young to hold onto the memory and his parents never knew the truth of what it was—but that was fine. Compared to the endless reaches of the multiverse and all the stars burning therein, it hardly mattered.
The first time either of Dean's parents heard him say the name and recognized it for what it was, or at least began to, he'd already progressed to full sentences. Mary, always a lighter sleeper than her husband, woke to the sound of a one-sided conversation over the baby monitor. Dean was telling someone about how they'd had cheeseburgers for dinner. It was probably just one of his stuffed toys, but it didn't hurt to check, and it was past midnight anyway; he needed to get settled back to bed.
When she got to Dean's room, instead of a toy, she found her son addressing the window from where he stood at the edge of his crib. Her heartbeat sharpened with sudden fear, but when she checked outside there were no prowlers lurking. Moonlight illuminated the yard enough for her to see that nothing was out of place, so she relaxed as Dean kept chattering on.
"Hey, angel," she interrupted softly. "Who're you talking to?"
"Cas!" Dean pointed out at—still nothing. Then said, "He's my star."
The stars were out and shining, barely dimmed by the comparison of the bright moon. Mary smiled up at them, following Dean's vague gesture. A kid could do worse for imaginary friends than a star, so she crouched next to the crib's railing and asked, "Yeah? Which one is he?"
She let him point out his 'Cas,' a star twinkling low between two treetops where he could see it even when he lay down. Then she coaxed him back to sleep, tucking him beneath the soft blue blanket and kissing the top of his head as he yawned two goodnights: one to her and one to Cas.
The next time Dean was awake with his dad after dark, he pointed Cas out to him, too. He even picked out the same star, though its position hadn't had time to move yet. John humored him with the same encouraging enthusiasm as Mary, asking what made that star Dean's ("He just is!") and how Dean knew its name ("Because that's his name, Daddy! He told me!").
If they'd expected Cas the star to be a fleeting fancy of Dean's imagination, they were proven wrong when Dean kept talking to and about his star not just for days, but months.
He'd bid it goodnight, even when the season carried it out of view of his bedroom window. And despite the season, despite never knowing which direction was north or which way home was, he could always locate it in the night sky with instant precision. It was one of the stars that never passed below the horizon as the year went on, eternally visible so long as the sky was clear and the sun was down.
When Sam was born and only just back from the hospital with Mary, Dean snuck into his nursery late at night and introduced him to Cas. Every day, though Sam was too young to understand, Dean would tell him fantastic stories about the stars and how they lived. His parents would listen in when they could, impressed with their son's vivid imagination.
A few years into Dean's fascination with his star Cas, they got him a reasonably cheap children's telescope for his birthday and let him stay up late to use it. The sky didn't cooperate that night, dark and gray without a single break in the clouds, but Dean still angled it where he said Cas would be and peered through the eyepiece at the offending darkness.
"I don't like when it's cloudy," he said after a while. "I can't talk to Cas. I miss him."
John reached out to ruffle Dean's hair. "The stars are still there even when you can't see 'em, kiddo. You can keep talking to Cas if you want to."
Dean ducked away from John's hand with a giggle and within another moment they were wrestling and tickling playfully. John scooped his son up around the middle and twirled him over the lawn, careful to keep a safe distance from the telescope as the two of them tumbled into the dew-damp grass.
But once the carefree joy quieted, Dean looked up at the sky again. Even in the dark, John could tell he was sadder than a boy celebrating his birthday ought to be.
"He can't hear me through the clouds. He doesn't like it either."
With the terrible, though ultimately incorrect, thought that Dean might be lonely, John tugged him closer. "We should get you to bed, but I'll tell you what. Next time we've got a nice night, you can come say hi to Cas properly. Okay?"
"Yeah!"
Dean grinned wider than anything but Sammy brought out of him when he could finally fix his telescopically enhanced gaze on Cas's area of the sky. He pulled back before too long to look up naturally and wave.
"Hi, Cas! You're even prettier up close."
The botanical garden blushing with spring was a sight to behold, but even the beauty of its flowers couldn't prepare the Winchesters for a stunningly gorgeous butterfly to land on Dean's left arm. Its wings, as dark blue as twilight with breathtaking spots of bright white, fluttered to a halt on the bare skin just below Dean's T-shirt sleeve.
Sam flapped at Dean to be careful, trying to sneak close for another look without scaring it off, but it seemed content to stay where it was, even when Dean lifted his shoulder to beam at it and exclaim, "Cas!"
That startled the rest of his family into silent puzzlement. Dean had never been shy when it came to talking about his so-called star. He still talked to Cas about his day when he was winding down for the night, and often wove stories for Sam about Cas's life as a star with all the other stars in the sky. With their parents' encouragement, he'd even started to write the stories down as he learned to read. They gave him a special journal with big lines and a pretty pattern of the night sky across its front, just for that.
But Cas, throughout the years of Dean's imagination, had always been a star. Cas had always been the exact same star. Suddenly having the name assigned to something else threw them; understandably so. Before any of them could make sense of it, Dean kept on talking.
"This is awesome! How are you here?" he asked the butterfly, waving the arm it sat on in a sweeping motion that covered the garden but indicated a broader sense of the world. It stayed put despite his wild movement. After a beat, his exuberant face fell a little. "Oh. Okay."
The butterfly lifted away, wings fluttering it up and out of sight as Dean waved goodbye. Despite his temporary melancholy, he perked up again quickly.
"Didja see?" he asked Mary excitedly. "It was Cas!"
Mary and John exchanged looks before she asked, a little cautious in her confusion, "I thought Cas was a star?"
Dean's head bobbed up and down. "Usually he is, but he figured out how to come see me during the day! But it's hard, so he couldn't stay very long."
More years passed, bringing Dean long past the time he should have given up on imaginary friends, but Cas remained a constant in his life. A somewhat inconstant constant; Cas was still the star Dean claimed as his own, but sometimes Cas was also a bluejay that landed on Dean's shoulder on an afternoon picnic. Or a fluffy squirrel that climbed him as unhesitantly as it jumped to a tree, then followed him around for an hour and jumped into the fall leaves as he raked them into piles.
Staring out the kitchen window on the latter occasion, John said, "Either I'm losing my mind or our son is Snow White. Or..."
"Or there might be something to Cas after all?" Mary finished when he couldn't. They kept watching in silence until the squirrel bounded onto Dean's shoulder again, chittered briefly at him, and disappeared up a branch.
So when a raven-dark stray cat with bright blue eyes showed up on their porch, and Dean opened the door and looked back at them hopefully, they let it stay for two days without Dean having to ask. It ate canned tuna, went outside to politely bury its business, and slept on Dean's bed.
"No allergies?" John asked the next morning, studying Dean's face for any sign of irritated redness.
"'Course not," Dean said with an easy grin, ripping off a bite of his toast and feeding it to the cat purring in his lap. "It's just Cas."
As excited as Dean got whenever Cas appeared in some new form, he hardly minded when Cas had to leave. He'd just start talking to him again as soon as night fell. Or, if the skies were dark with clouds, he'd spend an hour—or a few—writing in one of his now numerous star journals.
His storytelling improved as time went on, but the subject matter was always the same. It was always the story of Cas and the other stars like him—though from what Dean shared in his books, there were no other stars quite like Cas—and what they did, and what they saw out there in the universe.
Sam, also older and beyond more childish pursuits, still loved nothing more than to sit out under the night sky with Dean and listen to him tell a story of stars.
After the cat came a dog for a week, then nothing. For over a year, no new animal companions followed Dean home. His family would have worried, but Dean stayed in good spirits. His routine conversations with his star never faltered, despite the lack of any physical presence. Whatever was going on, he was fine and Cas was fine.
They didn't ask. It had always felt too delicate, the inexplicable link between Dean and Cas, to ask about. As soon as John and Mary had realized something deeper than childhood imagination was responsible for Dean's connection with a star, they'd left it unsaid. They lived in a world of science and reason, a world where magic didn't happen, yet somehow magic had found its way into their eldest son's life. If they gave voice to that anomaly, they feared it would vanish into the harsh truth of reality and Dean would suffer for it.
Dean was happy and grounded, despite his unusual circumstances. He did well in school, had other friends. The bond he shared with Cas, though strange, had never brought him to harm. After their initial surprise, and after reassuring themselves he was real and not a sign of psychosis, Dean's parents had grown fond of Cas—whoever, whatever he really was—for the joy his existence brought Dean.
Sam, maybe because he'd grown up with the stories of Dean's star, never questioned how such a thing had happened or the importance of keeping it private. Cas was Dean's, and Dean was Cas's, and that was just the way of things.
"You're sure you don't want us to take you out somewhere nice?" Mary asked one last time on Dean's eighteenth birthday. "It is a special occasion, after all."
"Yeah, and I want to spend it just here. With you guys. Eating pizza and watching movies where things blow up."
The sun had set and many, many things had blown up across two movies when someone rang the doorbell. Dean reached for the remote as Sam stood, but Sam waved him off.
"Dean, we've watched this entire franchise like five times now. I'll be back in a minute anyway, it's probably just someone campaigning for something."
When he opened the door, there was a man on the porch. Or maybe a boy. He looked to be close to Dean's age, but he also looked immeasurably older. Sam couldn't tell what it was about the visitor that gave the impression of endless eons, but his gaze passed over blue eyes and dark hair and went straight for the spot between the trees where Cas's star should have been. They'd all learned to track him over the years, though only Dean could do it effortlessly.
The familiar patch of sky was empty.
Sam's heart nearly leapt from his chest as he left the door hanging wide open and dashed back to the living room, yelling the whole way. "Dean. Dean!"
"What?" Already on his feet, Dean grabbed Sam's arms to slow him down before they collided. "I doubt Neil deGrasse Tyson stopped by for a visit, so who's got you so excited?"
Sam tugged himself free of Dean's grip only to reverse it, pulling his surprised brother down the hallway in his wake. Their parents followed more sedately, but no less curious. As soon as Dean got in sight of the door, Sam couldn't get him to move another step. Then, just as suddenly, he wrenched free from Sam's hand and bolted for the threshold.
The only thing surprising about Dean kissing Cas was that they didn't start shining with the brilliant light of the stars; all the other Winchesters, separately and in their own minds, found themselves expecting a radiance that never came, at least in a literal fashion. Dean's smile when the two finally pulled apart was radiance enough, it turned out.
"I'm sorry I took so long," Cas said, but Dean only kissed him again and answered, "I knew you'd make it to me someday, I wouldn't have even minded waiting until I was old and gray. But this is better. This is so much—"
Remembering their audience, he spun without letting go of Cas. Crimson stained his cheeks, equal parts embarrassment and passion, as he took in his family. To a one, they beamed right back at him, nothing but love and understanding. His whole life had been building to this, and though they hadn't known it, neither were they astonished by it. Like everything else about Dean and Cas together, it felt right.
The Winchesters, all five of them together, built a house for the two newly married among them. Dean made sure that every single room had large, open windows, and most got skylights, too; Cas swore he never missed his place among the stars, not when he could be with Dean, but he still loved to spend hours staring up at the sky and talking to his siblings still there. Though Dean couldn't hear them the way he'd always been able to hear Cas, he sometimes joined in regardless. After all, they were his family as much as Cas was a Winchester, and it also gave him a lovely opportunity to let Cas whisper their words back down into his ear.
Sam built a shelf around the wall of their bedroom, circling the entire small room. After he'd painted it with swirls of black and purple and blue, and sparkling dots of bright white, he lined it with the special journals Dean had written for as long as he'd known how. There weren't enough to fill it yet, but every star in the sky had as many stories as Cas, and he loved to share them with Dean as much as Dean loved to have him interpret for the others.
Cas filled the garden with trees and shrubs and wildflowers, because he'd loved all the creatures he'd formed himself into as he learned his way to becoming and staying human. He'd spend sunrise and sunset out in their yard talking to their animal visitors just as easily as he talked to his kin, and if anyone gave a thought to how strange it was for the young couple to attract so many beasts that oughtn't have even been on the continent, none of them mentioned it.
As for Mary and John, their contribution was a guest room filled with all the bright colors of the world that Cas said he loved to watch while looking down on the Earth. Sam stayed there as often as he did at their parents' house when he came home between semesters and degrees. Sometimes, if Dean's friends from high school passed back through town, they'd stay up half the night reminiscing and letting Cas in on their teenage mischief.
And years later, when a shooting star flickered out over their roof and a baby girl appeared on their doorstep, the room became a nursery with only a change in bed and title. She was pale and beautiful, wisps of red hair framing her round face even as an infant, and just like her daddy, the first name she ever said was Cas's.
"Pa!"