Rudy and Penny volunteer to baby-sit Rudy's little cousin Sophie,'Soph'. When Sophie draws a ChalkZone portal, she fall's in and starts to explore the land of ChalkZone while Rudy and Snap come up of ideas to get Sophie back to Rudy's house safely. Meanwhile, Penny comes up with elaborate scheme to make sure Rudy's mom and Sophie's mom don't find out about Rudy and Sophie being in ChalkZone.