Della urges Webby and Dewey to bring Penumbra with them to the pier after the kids learn of the grand opening of the Flintferris Glomwheel, Glomgold’s latest gift to Duckburg. Penumbra is reluctant to join the children in their “Earth fun”, but changes her mind after being criticized by her fellow Moonlanders for her stoic attitude. At the pier, Webby struggles to encourage Penumbra to appreciate her new life on Earth, but experiences a breakthrough after she confides in her that she has learned to be more than just “Mansion Webby”. Her success proves temporary however, as Penumbra grows frustrated with Earth once again, and is then used by Glomgold as a scapegoat when a safety inspector deems the Glomwheel dangerous. In the ensuing chaos, Webby and Dewey end up trapped onboard the Glomwheel, which turns out to be a cannon aimed at McDuck Manor and is collapsing due to its shoddy workmanship. Spurred on by the crisis, Penumbra rescues her friends with the aid of Launchpad and fellow Moonlander Gibbous, and embraces her new purpose as a protector of Earth.