From the publisher:
Ruggedo, the wicked old Gnome King, escapes from Runaway Island and sets out to reclaim his own kingdom and ravage Oz. Together with Peter, an unsuspecting lad from Philadelphia, he discovers the magic casket of Soob the Sorcerer and a flying cloak of Invisibility.
Meanwhile, Scraps, the extraordinary Patchwork Girl of Oz, has been kidnapped from the Emerald City. Along with Peter, Grumpy the Bear, and Ozwold the Oztrich, she tries to save the capital of Oz before Ruggedo's new sorcery can take effect. But it's up to Peter and his baseball pitching skill to make the final stand against the Gnome King of Oz!