If Cas Comes Back
If Cas comes back, reflected within his eyes every time Dean looks into them might be the water the he was ingulfed in to, Dean might see the ripples that were the only proof that Cas's body had been there seconds before, the all-too-familiar trench-coat submerged in the seemingly colourless water, and how he stood watching his friend disappear. Dean would be reminded of how each night - knowing Castiel was gone - no peace would find him, the smell, that Dean had subconsciously associated with comfort, he half-thought he'd created within his mind that lingered beneath his head as he slept, of how each time Sam would open his mouth to say something, only to shut it again with a small frown upon his face, he'd want to scream with frustration pleading for Sam to yell at him, to tell him he should have done something, anything, he'd want Sam to tell him anything that would provide even a fraction of relief from the pressure that tightened his gut where his swallowed anger boiled.
But then...Cas'd blink and Dean would come back to the present. Cas might ask what was on Dean's mind, or he wouldn't - already knowing that distant and haunted look on his face.
Dean'd feel almost so deflated with relief that Castiel was there, with him, that he'd breath out - not realising he'd even been holding it in - and smile, rubbing the back of his neck. He'd clasp Cas on the shoulder and maybe proposition a game of poker before they called it a night. Sam would grin knowingly at that contact between them, being sure that it masked so much more just underneath the surface.
Maybe Dean would try and get Cas to play - thinking maybe he'd actually have a shot considering his hardly faltering poker face.
No, if Cas came back the blue of his eyes would never fail to wrench Dean back to that agonizing time, but every time Dean's resultant smile would never fail to make Cas's insides squirm at the fact that Dean ishappy - an emotion that had never truly captured Dean's heart - all because of him.