The viewers get to learn about having imaginary friends.
This episode introduces viewers to Polka Dots, a small, stuffed green dog toy of Blue's with purple polka dots, who previously appeared in some of the Blue's Clues episodes. They also learn more about Joe's stuffed duck, Boris. Joe and Blue play pretend with Slippery, learning that using their imagination and perhaps their own stuffed friend, they can do anything that they want to do. Then, Joe and Blue meet Periwinkle's friend, Mr. Plate, and visit new places and situations with the two of them.