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.
Janet Asimov (maiden name Janet Opal Jeppson, born 1926) is an American science fiction author, psychiatrist, and a psychoanalyst.
Janet Asimov started writing children's science fiction under the name J. O. Jeppson in the 1970s. She was married to Isaac Asimov from 1973 until his death in 1992, and they collaborated on a number of science fiction books aimed at young readers, including the Norby series.
Janet Asimov. Wikipedia.