It's Halloween, but Jessy and Nessy are distracted from their trick or treating by a very stinky mist. Unless they can figure out where this stink is coming from, it's going to ruin Halloween! Jessy and her pals are trying to paint a picture for Nessy's room, and are looking for a yellow crayon. Their search reveals that all the colors in Cara Park are switching around. What is going on? And why?