The boys give chase, naturally, and they're soon joined by Rufus and Bobby, who came running out of the depressingly familiar break room at the first sound of gunfire. Rufus insists upon retrieving his shotgun, however, so Sam and Dean jog off by themselves while Bobby and Rufus return to the depressingly familiar break room to jimmy open that padlock, with Rufus carping away at Bobby the entire time for locking up their guns in the first place. Sam and Dean eventually rejoin them, their hunt for Zombie Grandpa having proved useless, and the four strategize for a few quick moments before dashing back out onto the factory floor. And it seems Zombie Grandpa's been quite the busy little geriatric over the last couple of seconds, because they almost immediately stumble across a tripwire the old coot'd rigged up to, like, drop a garbage can onto their heads, or something? It's not clear. "ZZZZZZZZZZZZZ!" That, too. In any event, the four successfully sidestep the trap, only to have Sam get cut off from the others when a large door unexpectedly trundles shut behind him the instant he crosses a particularly inconvenient threshold. Sam shouts that he'll somehow manage to work his way back around to meet them, and it occurs to me that I should probably be worried about his welfare at this moment. Then it occurs to me that there's no way in hell they're going to kill off one of their leads in the middle of this crappy episode, and I instead start thinking again about joining Raoul in his Coma Of Boredom. "ZZZZZZZZZZZZZ!"
Eventually, and after a very long while, Sam at last finds Zombie Grandpa lurking in the shadows, and after Zombie Grandpa unleashes a lengthy series of taunts and sneers I'll not be bothering to transcribe, Sam shoots him in the head.
Well, that certainly was anticlimactic. "ZZZZZZZZZZZZZ!" Yeah, yeah: And boring, too. Not to mention deeply, deeply unsatisfying. I've been waiting six goddamned months for them to off the goddamned bastard, and that's all I get? Even the METAL TEETH CHOMP! is so disgusted with how this all turned out that it can't be bothered to escort us into this evening's next commercial break.
Cannery. Immediate aftermath, again. Dean comes a-running at the sound of gunfire, his bitty little flashlight bobbing all the way, and he's most relieved to find Zombie Grandpa dead. As is Bobby, who toddles on over a few moments after Dean's arrived. Rufus, who appears last, doesn't seem to care much one way or the other, but that's not important right now, because what is important right now is the fact that Bobby's relief immediately slides into suspicion when he realizes Sam's most likely been infected with the homicidal demonic earworm.