Yes, precisely! Sam's acting like an asshole cause he's worried, and it's already awkward because of what happened while he was gone, and he's been kinda prickly and suspicious anyway because the Dean/Jess issues haven't come out in the open yet, so he doesn't take kindly to feeling like Dean's ganging up on him, and Jess can't figure out why he's acting differently since he came back.

I lean toward zombie apocalypse just because I desperately, desperately don't want to just do a retread of mythology on the show, devoting too much time to their roles in it, angels/Lucifer etc. Something more along the zombie lines appeals to me because then they're just normal people trying to survive all the CRAZY SHIT that's raining down. Your thoughts?