Dean Winchester is not what anyone expects of a god: plaid and leather and old cracked boots, the burn of whiskey and the rumble of a classic car. Steve asks Dean what he is god of and Dean laughs. He leaves, a swirl of dust behind him on the road, without answering.

He is the god of the road and hunters everywhere, the god of subculture and secrets whispered of in back alleys and run-down bars. If they don't know that when they meet him, they are not one of his.

In New York, Sam laughs too. Unlike Dean it isn't a kindly one. His secrets aren't benign. Where Dean is the smooth smoky slide of booze, Sam is sharp afterbite and the piercing hangover. He is the scratch of a thousand sharp claws and the scream of terror in the night. He is the cuckoo in the nest.

Dean still calls him brother, but the Avengers don't understand it. They don't understand him, either. He drifts in and out of their lives gun at the ready, always happy to help but also dreaming to leave. The road pulses through his veins.

"You know, this room is open for more than a few days at a time," Tony tells Dean one day. The morning before they had taken on a Hydra base, laughing in exhilaration as they burned it down around them. Dean smiles, but he can't stay. The road calls, along with a thousand desperate curses from hunters whose hands shake with adrenaline. Dean will not save them all (Sam will get there first) but he can always save a few.

When his heart isn't on the road, it's set another direction. But Dad says things about balance and harmony, and keeps the paths closed. He says, You have to kill your brother, Dean, and Dean barricades the way from the other side.

Nobody touches his brother. Family is everything to a hunter.

That isn't to say he won't give Sam a good smack when he deserves it – calling the Chitauri from another dimension, for example. Dean gave him a wallop for that. (Sam gave him almost as good of one back.) But he also wasn't surprised when the Avengers descended on the ruins of the Stark Tower penthouse and Sam flitted away as easy as one of his demons.

Even if he hadn't disappeared, Ruby would have broken him out in due course. She's learned runes to keep her presence hidden, but Dean hasn't let on yet that he's stated to identify her hosts by the subtle flickers of sardonic humor Ruby can't properly hide – like the one he saw on Agent Hill's face when they first met. Dean leaves her there, because he never knows when he might need to make Sam come running, and a sharp knife against the neck of his favorite confidant should do the trick.

In the meantime, Dean waits for the times when Sam appears. He helps the Avengers when they need him and follows the invocations of hunters from coast to coast while he waits – but the minute Sam appears, Dean is back in New York, suiting up with the rest of the Avengers to just get a moment with his brother.

"You can come back," he tells Sam between punches. "I still love you, brother. We should be on the road together."

"And what about when Dad tells you to kill me?" Sam snarls, and slashes with Ruby's knife.

Dean takes the hit on the shoulder so he can reach in with his other hand and grasp Sam's wrist. "I mean it. Come with me. I don't care what dad says."

Dean leaps back to avoid the stab at his ribs. Then Sam has disappeared again, leaving the Avengers to clear up his squadron of shapeshifters. (Skrull, SHIELD intelligence tells them later. Alien shapeshifters from another planet. Dean keeps quiet.)

Purgatory summons Dean like a siren song, but Dad has barricaded the door and Sammy's not there any longer. So Dean wanders, and hunts, and waits. Sam will come back to him eventually.