When unscrupulous scientists try to kidnap Norby in order to learn the secret of the robot's anti-gravitational capabilities, he and Jeff discover on the dragon-inhabited planet Jamya the key to an even more precious secret.

A Space Academy student and his time-travelling robot stop an evil villain from taking over the Solar System in this children’s sci-fi classic. Fourteen-year-old Jeff Wells, a cadet at the Space Academy on Mars, is in danger of being kicked out unless he can improve his grades. With a little help from the academy’s commandant, Jeff finds a robot named Norby to help him study. But Norby’s no ordinary robot. He has the only mini-anti-gravity device in existence. Norby’s special abilities suddenly come in handy when a villain named Ing targets Jeff’s older brother in his quest to conquer the Solar System. When Ing takes over Manhattan Island, renaming it “the Kingdom of Ing,” Norby and Jeff put studying aside to teach Ing a lesson!

In the second volume of the complete children’s sci-fi series, a boy and his robot venture to a dangerous planet and go in search of a missing princess. Norby’s Other Secret Scheming scientists want to find the secrets behind Norby’s antigravity abilities, but they have to dismantle him to do it! To evade them, Norby and Jeff flee to the planet Jamya, where Norby was created. But can these friends survive a planet is inhabited by angry robots and intelligent, hungry dragons? Norby and the Lost Princess Jeff and Norby travel unintentionally to the distant planet Izz, where they are forced to join a search for the missing princess. Their journey takes them to the muddy world of the Slithers, strange creatures who imprison the travelers, sting them into submission, and communicate with them only through musical sounds. Then things go from bad to worse when they discover that the missing princess has been turned into a tree!

Jeff Wells purchases a used robot named Norby to help him improve his grades at the Space Academy, but learns that Norby was constructed by a genius using parts from an alien spacecraft and has unexpected powers

Jeff and his mixed-up robot, Norby, get involved in new adventures on a strange planet.