Sam was persuaded that all those visions, all those nightmares meant something. It had to be; because if not, did it mean he was going insane? That something was wrong with him? And when he had that nightmare of that garage, of that crime -- he had to see for himself if it was really, if he was right to be puzzled by all of this.
And maybe he was, because when him and Dean got to Saginaw in Michigan, Jim was already dead -- and all the neighbors kept saying it was sad what he had done, that he left that way... But Sam knew better. Even if Dean didn't believe him, even if nothing seemed paranormal here.
To investigate better, they had to talk to the mourning family and what better than pretend to be Priests for that? The next morning, both Sam and Dean were at the door, to meet the rest of the Miller's. What Sam gathered was that Max, the dead man's son, found him so he excused himself to talk to him while Dean pretexted to want to wash his hands upstairs.
There was nothing coming from Max, he was stoic -- the house was perfect and shown no weird past history. So Sam said his goodbyes to Max and was ready to leave to find Dean before he heard a voice behind his back, calling Father to him.
The goddamn Priest costume.
Sam turned around to see you, you had been presented as a family's friend by Alice Miller earlier, and Hell, you seemed to want to speak with Sam. Not Sam Winchester, no, Sam the Priest. What was he supposed to do now? He couldn't blow his character off, not now, not here.
"Uhm—yes? Do you wish to speak to me?" he asked you, a bit uncomfortable, sweating under his clothes. And where the fuck was Dean, anyway? And how Priest usually acted, too?