Jeff and Norby, accompanied by two friends, rush off to Jamya to help Norby's ancestor, Mentor First. But their mission becomes complicated when the Grand Dragon of Jamya is whisked off to another planet by strange alien creatures known as the Hleno. These blimplike creatures, at home in water or air, believe themselves to be protecting the environment from excessive uses and abuses of technology. Norby and Jeff are taken prisoners, too, along with Jeff's pet, Oola. Encased in an impenetrable plastic bubble, Norby is helpless.