Hey everyone! I wrote this in response to a Tumblr post and I ended up liking this a lot so... you get it here.

Disclaimer: I don't own this whole Supernatural thing. Apparently.

"Cas, you're my best friend, you know that?" Cas smiles his lopsided smile at Dean and tilts his head.

"You're mine too, Dean." The two are sitting outside underneath the huge oak tree, surrounded by their collection of X-Men and G.I. Joes and race cars. Cas looks up into the leaves and leans back on his hands. Dean notices where his friend's attentions have gone and he too looks up.

"Watcha thinkin' about, Cas?"

"Nothin'. Was just thinkin' about how cool it'd be to climb that tree. You could probably see up to space from that high." Dean looks from his friend to the branch that Cas points to. It's awfully high and Dean's never particularly been fond of heights. But, if his best friend wanted to see space, he would go with him. He stood up abruptly and grabs Cas's hand, hauling him up as well. He grabs the first branch and hoists himself up, already reaching for the next one. He looks back to where Cas stands on the ground, looking at him with an unreadable expression.

"You comin' or what?" Cas blinks and his expression changes, turning to one of unadulterated happiness. He quickly follows behind and soon the two of them are balancing on a branch halfway up, clinging to the tree and each other's hands as they survey the new vantage point.

"Well, you can't see space up here, but it's still pretty cool." Dean looks over at his friend and grins.

"Someday, we'll climb the entire tree. All the way up. Then you can see space. You could probably fly!" Cas pegs him with a dubious look… right before he loses his balance.

Dean's eyes widen in horror as his friend is suddenly gone from the tree and a thump is heard on the ground, followed by a muffled, "Woah." He quickly climbs down and is by Cas's side in a second.

"You okay, buddy?" Cas nods, his ten year old body just having suffered some minor scrapes. Cas sits up and looks up at the tree again.

"I hate trees." Dean laughs.

"They're okay. My dad used to carve things into the trunk and then years later, it'll still be there!" Cas looks at him incredulously.

"Really? It'll be there forever?" Dean nods and runs inside briefly to grab his dad's pocket knife. He returns and pulls Cas around to the side of the tree that won't be seen from the house or the street. With some difficulty, he carves into the tree's trunk,

DW + CN

When he is finished, Cas traces the letters with his finger.

"Those are our initials." Dean nods happily.

"Yep! Because we're gonna be friends forever!" Cas smiles and pushes him playfully. The knife is dropped and the two run around the tree in a game of tag.

…

Dean looks at the carving and smiles. The tree was still here and the carving still in place. He set his parcel on the ground and looked up into the leaves where the branch halfway up still sits. He easily grabs the branch and hauls himself up. He's not ten anymore, far from it, but even at forty he can still climb this tree. As he lounges on the branch, he looks around. This is where he first told Cas he thought he liked guys and girls when he was fourteen. He smiled as he remembered Cas telling him that "Of course you do, because you can't ever decide on one thing."

He remembered being sixteen and sitting on the ground, leafing through a magazine while Cas sat on his other side, engrossed in his textbooks, and Dean suddenly was struck by the urge to kiss Cas. So, he set the magazine down, tipped Cas's book away from him, ignored Cas's resulting cry of protest and kissed him soundly on the mouth. His expression had been hilarious and the subsequent series of kisses after that made Dean wonder why he hadn't done that sooner.

He remembered being seventeen and pushing Cas up against the very same tree and licking into his mouth with a fervor that was matched only by Cas. He had a hard enough time keeping his hands off Cas in public anyway, he couldn't be expected to do so at his own house. He remembered feeling like he could stay forever here. He felt like he was flying and even though he and Cas had never quite climbed high enough to see into space, he felt that they got pretty close.

He remembered being eighteen and hugging Cas and telling him about his deployment. Cas had cried and Dean tried not to follow as Cas kissed him softly and walked away, leaving him under the tree. He remembered feeling dejected and kicking the tree.

He remembered being twenty two and pulling up to the drive of his house. In his army uniform, he walked up to the door of his house, shoulders squared. He happened to look over to the side and saw Cas sitting under the tree, book in hand, as always. Even though it was Dean's house, Cas never seemed to feel unwelcome there. He paused, but took two long strides towards the tree, which turned into a fast run and he called out Cas's name. Cas looked up, confused, but his eyes widened as he saw who was coming for him. He stood up quickly and practically jumped on Dean when he came close enough. They stood under the tree for an hour and kissed each other and murmured how much they had missed the other.

He remembered being twenty five and stuttering and completely messing up everything he was trying to remember to say before he shakily went down on one knee and asked Cas to stay with him forever. He remembered being pushed against the trunk, right against where their names were carved and being kissed so thoroughly, Sam had laughed at his dopey expression that he wore into the house and most of the next week.

Dean dropped down from the branch, landing gracefully on his feet. He picked up the parcel at the base of the tree and walking around to the side where the carving still sat, proud to last through the ages. He knelt at the base of the tree and started digging with the trowel he had brought.

He remembered being thirty and sitting sprawled under the tree with Cas, looking up at the leaves like all those years ago. He looked over and saw Cas looking back at him with that gentle adoration that never left his gaze, even after all these years. He reached down and twined their fingers together. Cas asked him if he remembered when they tried to get to space from the tree limbs and Dean laughed and nodded. Cas said that he reckoned flying and seeing outer space would still be pretty cool. Dean agreed and made Cas promise that if he got to fly and see outer space, he would at least wait for Dean before he got to the cool stuff. Cas's chuckle dissolved into one of his coughing spells that never seemed to really go away.

He remembered being forty and sitting with Cas out under this very tree and just sitting. Just thinking. Trying not to imagine life without Cas, but failing whenever Cas took one of his stuttering breaths through his machine. He remembered clutching Cas's hand tightly, the wedding band loose on his finger, and murmuring that everything was going to be okay and knowing he was lying. He remembered pressing his lips to Cas's temple as Cas smiled weakly at him and holding back the tears as he returned that smile. He remembered Cas reaching for his hand and looking up and saying that he wished he could fly right about now.

He remembers being forty but feeling about ninety years old with the crushing weight on his shoulders as he rushes by that old tree. Cas's breaths are starting to come fewer and farther between. He vaguely hears Sam yelling for Jess to call Bobby but the only sound that really has his attention is the stuttering breathing of the figure in his arms. He tells Cas to hang on, just hang on a little bit longer for him, pleading with him not to leave him like this. He remembers Cas reaching up weakly and brushing his cheek with his hand, wiping away tears he didn't remember shedding. As he loads Cas into the front seat and darts around to the driver's seat, he spares a glance to the tree, not able to see where their initials are carved, something he had gotten into the habit of always looking for.

He remembers seeing that tree again two days later as he pulls into the driveway, alone.

Dean placed the box of ashes in the hole and quickly covered it again with dirt. He took the ring that was sitting on the ground and held it in his hand for a moment. He took off his necklace and strung the ring on it, the metal clanking against the strange symbol that had come from Sam. He stood up and wiped the dirt from his jeans, twisting his own ring around his finger as he did. He glanced up at the leaves, wondering what Cas would think right about now. He hoped Cas was flying. The mound of dirt was directly below the carving. Dean cocked his head at the carving. Something about it wasn't right. He studied it for a moment and knew what was missing.

He took his dad's knife from his pocket and quickly carved into the wood. When he stepped back, he smiled. A heart now surrounded their initials and the N which had once stood for Novak had now been changed to a W to match Dean's for Winchester.

DW + CW

He swiped the stray tears from his eyes and went back in the house, he heard the voices of Sam and his family calling him inside for lunch. After lunch, he laid down on his side of their bed and rolled to face where Cas would have lain beside him. He closed his eyes and dreamt of flying and outer space and silly childish things and Cas. Always Cas.

Sam remembered being thirty six and walking into the room that his brother had shared with Cas about a week after Cas's death. His brother's form was clearly outlined under the blankets on his side of the once-shared bed. The blankets weren't moving like they should be and at once, Sam knew they had to get another space under the tree.

Hey, you know what's cool? Reviewing my stuff. That's real cool.