Mark's exodus continues, with the help of every animal still dwelling in the swamp. He has no discernable reason to believe that those sad sacks on the boat are smuggling anything, but if he doesn't come up with some illegal activity, there's no justification for returning to the boat in Pop's "swamp buggy" to punch their faces. So smuggling it is.
Meanwhile, back at the swamp house, Pop is talking about how he's going to look for Mark with what we have to assume is a dual personality, but Sue's non-exclamatory response says it all -- Pop is soooo full of shit. Strange installment indeed.