Wow.  Just, wow.  This strip is sooooo busy.  I think there’s a certain charm to it, but hold crud, those panels are just loaded.  Usually not a good idea.
I have no idea why the Space Pig is singing “Last Kiss.”  That was the song that seemed to fit and once I got the idea of using it, I couldn’t hear any other song in my head until it was done.  The Pearl Jam version, in case you’re interested.
That last panel is a setup, obviously.  Payoff to come in Chapter 5.