What kind of brothers are we, if not brothers by heart?

Seated in the passenger seat of the Impala, Sam glances across the expanse of the car towards Dean. When did things change between them? Is there any chance at regaining that brotherly affection they used to share, or has time altered their relationship beyond fixing? Based off Sam and Dean as of 9x15; will develop into the constellations of my own mind. Chapter 2: with young S&D!