One Day (слэш)

Once upon a time, Steve and Bucky began and ended every mission with the same few words pressed against eager lips. It was a promise and protection both, a ritual repeated time and again to ensure that they would always make it back to each other. Only one day Bucky didn't make it back and subsequently Steve's whole world fell apart.
It was stupid, really, to have placed so much faith in something so insubstantial, and yet, perhaps there was more power in words than Steve could ever have imagined...