Howard sends Rio, Rina and Anya to work at the Sky Resort casino situated at the top of a mountain. Once there, they meet the resort's dealer, Linda, who gives them a tour of the facilities. She is soon revealed to be a robot, and the resort's main terminal. The resort opens the next day, floating itself and its customers high into the sky. Just then, a boy reprograms Linda to challenge Rio to a Gate Battle in which they must both race each other down a giant water slide. The match is a close call throughout, with Linda manipulating the course to catch up; however, Rio wins when Linda loses her head. After the boy relinquishes control of Linda, the mastermind, Cartia Goltschmitt, approaches Howard.
島の山頂に作られたスカイリゾートが、いよいよオープン！ リオたちは、ハワードの命令で、このスカイリゾートに勤めることになる。広大なカジノフロアにホログラムシアター、スリル満点のエクストリームスライダーといった最新鋭の設備の数々。そして宙に浮くリゾート、ロボットディーラーのリンダの登場に、目を丸くするリオたち。しかし、華やかにオープニングセレモニーが開かれるなか、リオたちの姿を見つめる怪しげな連中が……！
