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.
Wait a minute. Let me repeat that: Homicidal demonic earworm. Jesus H. Christ on a stick.
ANY-way, where was I? Oh, yes: "Drop the gun," Bobby orders and, after Sam's complied, Rufus carefully steps forward to slip a pair of nylon restraints around Sam's wrists. "It's in him!" Sam insists, gesturing as best he can down towards Zombie Grandpa's rapidly cooling corpse. "Are you sure?" Bobby asks. "Yeah!" Sam replies, furiously nodding his head. "You see anything come out of him after he dropped?" Rufus wonders. Sam did not, so the gentlemen still breathing haul Zombie Grandpa's dead ass back to the...
...depressingly familiar break room, where they spread the corpse out on the table so Bobby might probe its ear-hole with a cotton swab. "Tell me you got something," Dean pleads. Bobby is very sad to admit he does not, for the swab emerges from Dead Zombie Grandpa's ear canal entirely devoid of bitterly black demonic goo. "You got a cranial saw in the car?" Rufus wonders for what I'm hoping are obvious reasons. "Of course!" Bobby growls, insulted that Rufus would even think to ask. The two of them head back out into the parking lot to grab the saw, leaving Our Intrepid Heroes alone to ruminate over Dead Zombie Grandpa's dead ass, and there's some extremely boring chatter about The Meaning Of Family, the likes of which we've heard at least eighteen thousand times over the past five and a half years on this show, and then Bobby and Rufus return to crack open Dead Zombie Grandpa's skull. Bobby shoos the boys out of the room, lest the impending post mortem offend their delicate sensibilities, so Sam and Dean trudge out into the corridor while Bobby and Rufus get down to work.