Penny joins Tinny and Nitty after they discover a balloon egg in the garden, resulting in the hatching of the baby balloon dinosaur Torii. Penny accompanies the group on their quest to return Torii to the balloon animal world above the clouds. This journey entails traveling through golden cumulonimbus clouds to reach the land of balloon dinosaurs. While navigating this realm, Penny reunites with companions from previous adventures, including the forgetful Rabby. The group arrives at Torii's homeland, the country of the Triceratops. Penny aids in the search for Torii's parents within this region. During this time, Penny becomes entangled in the unexplained theft of multiple balloon dinosaur eggs occurring in the Triceratops territory.