In the Kingdom of Oriana, Princess Oriana Marbry Steward, ruler of the realm, receives a dire warning from a local fortune-teller Alice Playten Pearl: her evil uncle, Peter Newman as the Duke of Zill, is marching on the land. To counter the threat, Oriana and Pearl descend into the cavern beneath the castle to operate an ancient device called the Dimensporter in hopes of slipping into another dimension and finding a hero to save them. But the Duke’s robotic army closes in, and the two are captured, with the Duke seizing control of the kingdom as his Cylinder robots haul Oriana away. The moment of capture is marked by a magical tear shed by the princess: it flies into the Dimensporter in her place and is transported to Felix the Cat David Kolin’s dimension, where the feline naps beneath a palm tree.
The tear wakes Felix, and guides him toward a forgotten gold mine where the Dimensporter lies. With his magical bag at his side, Felix is soon transported to Oriana, entering a world suddenly full of danger and promise. Meanwhile, Felix’s nemesis, Chris Phillips The Professor, along with his nephew Poindexter, who had been spying on him, follow Felix to Oriana in hopes of catching him and stealing the magic bag. Once in Oriana, the tear cannot guide Felix any further and vanishes. Felix gets lost and ends up in a swamp in the Land of Zill, where he meets Pim, who offers to guide him, only to betray him later and hand him over to Wack Lizardi, the circus owner and a loyal lackey of the Duke Peter Newman. At Pim’s suggestion, Wack confiscates Felix’s bag and puts him to work as a performer, locking him in a cell before and after every show.
Felix eventually manages to slip out of his cell and reunites with the princess, who is being held in an adjacent cell. She explains that the Duke has conquered her kingdom and reveals that the Duke is actually her uncle. In the past, the Duke was a scientist who clashed with Oriana’s pacifist traditions; after a laboratory accident left him disfigured, he rebuilt his body into a mechanical shell. He sought the royal secrets of their ancestors’ high technology, was banished to the Land of Zill, and returned with a mechanized army and a vow of revenge. Not content with merely ruling Oriana, he continues hunting for the royal secrets contained in the Book of Ultimate Power, which Oriana has refused to reveal. Felix escapes with the princess, using his bag to fly away in the middle of a stage performance. The trio—Felix, Oriana, and a reformed Pim—set off toward Oriana, joined along the way by The Professor and Poindexter after they fail to steal Felix’s bag.
The heroes infiltrate the castle but are quickly subdued by the Duke’s army. The Duke forces Oriana to reveal the location of the Book of Ultimate Power; once obtained, its contents prove useless to him. Enraged, the Duke unleashes his ultimate creation, Master Cylinder, to destroy the intruders, but Felix hurls the Book at the Master Cylinder, causing a short circuit that breaks it down and shuts down the rest of the Cylinders. With his army gone, the Duke flees, swearing to return. The kingdom is saved, and Oriana uses the Dimensporter to transport Felix, The Professor, and Poindexter back home.
