User blog comment:Gravityfalls iscool/What will happen in the apocalypse?/@comment-11643042-20150504014206

I realized something about the last two episodes. Long story short, even though Stan's countdown has expired, McGucket's countdown still has about an hour and a half left. However, judging by the few hints we have at the next episode, I wouldn't be shocked if they just had Grunkle Stan say "OK Mabel, NOW you can shut it down." That's the short version of my theory.