In response to maygra's Supernatural fic challenge.

My song was "Promises, Promises" by Naked Eyes

The road was familiar to Dean, though it would be a surprise to Sam to know it. It was one of the silent rituals of the Winchester clan; checking up on Sam. Neither of the older Winchesters discussed their visits with one another; it was enough to read the body language of the other, to see the decrease in tension. For now, Sam was safe; it was enough for them both.

Dean didn't know what was going on in his father's head when he visited campus, but he knew what drew him back time and time again. It was a promise he had made as a very small boy to keep his brother safe. He had never forgotten the promise and stayed true to it even after Sam had fled.

Dean thought it was kind of ironic that a promise could mean so much to him when it meant so very little to the man who had shaped and guided their lives. Maybe that was why he clung to it so fiercely. Dean had a very clear understanding of before and after – Dad before the fire and Dad after. Dad from before understood the power of a promise and he never failed to follow through. Dad after…well, he said all sorts of things, but his words were never as powerful as the hunt that drew him ever onward. Dean learned quickly not to ask for things he couldn't have; he learned not to count on Dad providing anything outside of the hunt. Sam had somehow never learned.

Looking back on it, Dean could see how it was sort of his fault. Sam would ask Dad for something, Dad would make some vague reassurance, and Dean would step in to provide whatever it was Sam wanted to the best of his limited ability. Bedtime stories and playing catch were easy to deal with, puppies and bicycles were much harder to provide. But Dean always came up with a solution that was acceptable to Sammy, and Sam came to depend on Dean to keep the promises made between them. But it didn't stop Sam from pestering Dad, or calling him out on the things he said he would provide. College was one of those things, and they all knew how that had turned out.

Dean smoothly guided the Impala off the exit ramp and down the familiar road that led to the off-campus housing. There were a lot of things Dad had never been able to provide for Sam; all of the things he'd promised out loud, the words he used had no real meaning once they left his mouth. But there were unspoken promises that held much more power than insincere words. Those unspoken promises had never been broken; in those promises he had never failed Dean – he always came back. Dean learned on the night of Mary's death that nothing was more important to him than the baby in his arms and the father who protected them both. And every time John returned from a hunt just reinforced the idea more strongly in Dean's mind – he would have everything he ever needed, as long as Dad came back.

Dad always kept his promises when it came to hunting. Find the bad things. Kill the bad things. Stay safe. Come home. Those were the foundation of Dean's existence, and when he started hunting on his own, he adopted them as his own. Those unspoken promises gave Dean an internal compass, a North Star in his unstable life. Find the bad things. Kill the bad things. Stay safe. Come home.

But this time, Dad hadn't come home, and Dean was lost.

Dean drew the Impala into a spot in front of Sam's building. He turned off the engine and laid his head against his arms crossed on the steering wheel. He didn't want to do this, but Sam had to know. And Dean knew he needed Sam's help. Those were the excuses he could give Sam, and Sam might even believe him. But deep in his soul Dean knew what drew him here tonight was the promise he made every time Dad stepped out of whatever seedy motel room they had camped in – I'll take care of Sammy, Dad. I promise.

John Winchester might not have believed in the strength of a promise, but his son did. With resolution Dean climbed out of his car and jogged up the front steps of Sam's building. Each footfall was accompanied by a promise in his head.

Find the bad things.

Kill the bad things.

Stay safe.

Come home.

I'll bring you home, Sammy. I promise. It was a promise he didn't realize he could never keep.