Agent Two Gridlow and Cadet Jefferson Wells are in the office of Admiral Yobo, head of Space Command, the military branch of the Solar Federation. Jeff is in trouble ("You are trouble") because he's disabled the kitchen computers by accident ("Accident? Hah!"). His older brother and only surviving family member Fargo is called in to arrange for his temporary dismissal from Space Academy. Admiral Yobo kindly gives him enough money for a teaching robot, but insists that he stay on Earth for the summer.
So Jeff picks up a used robot and names him Norby. While Jeff and Norby are discovering the unusual abilities built into him, they're also attacked by minions of Ing the Ingrate, a terrorist leader who wishes to become Emperor of the solar system. While avoiding capture, Jeff and Norby discover a built-in hyperdrive, Touch Telepathy, and that Norby is a bit mixed-up. Together with their friends and newfound powers, they stop Ing and reveal his true identity.
Norby, the Mixed-Up Robot contains examples of the following tropes:
- Audio Adaptation: There is a vinyl LP recording (only includes the first two chapters) with Mark Hamill as narrator.
- Auto-Kitchen: Space Academy (and even apartments on Manhattan's 5th avenue) are equipped with computers/robots that perform most of the duties for cooking. It leads to problems for Jeff that he's so bad at learning Martian Colony Swahili that when he programmed a sleep-learning device, it accidentally hooked into the kitchen computer and downloaded classified information from Space Command and translated them into Martian while downloading the recipes into his head (without any help at translate, so the only reason he knows they're recipes is that he's eaten Martian cooking before). Admiral Yobo, in charge of the Space Academy, won't be able to get a decent meal until this can be fixed.
- Dedication: The start of the book dedicates this to "all who like our robot stories", including H. Read Evans and Robert E Warrick.
- Dramatic Unmask: The Wells brothers launch a two-pronged attack, with Jeff in Admiral Yobo's private scout ship through the window and Fargo leading a mob through the doors, catching Ing in between. Norby lands himself on top of Ing, knocking off his mask in the process, revealing him to be Gridlow, the agent who tried to expel Jeff in the first chapter.
- Fun with Acronyms: TGAF shows up in the first chapter, which Jeff claims is meant to reassure him that all difficulties can be overcome. When challenged on this (the initials dont match), Jeff makes a backronym; The Girls Are Findable, because his older brother is so handsome. In the next chapter, it's revealed to be an initialism for a line from Henry V, "The game's afoot".
- "It" Is Dehumanizing: The manager of the used robot shop always refers to Norby as an "it". Most people usually refer to robots as an "it" because they have no gender, but Norby objects because the lack of respect implies he isn't a person. Jeff starts saying he/him immediately, while it takes a bit longer for Fargo and others to change.
- Language Barrier: When first arriving on Jamyn, Jeff doesn't speak the language, but Norby does. One of the dragons bites him, which Norby realizes gives him Touch Telepathy with other telepathic creatures.
- Lie Detector: The truth wand used by Ing's minions will hurt you if you tell a lie. A mild shock for a small lie, and bigger shocks for bigger lies. Fargo
- Line-of-Sight Name: When Jeff purchases the titular robot, it looks like a dingy barrel with the old label "Norb's Nails" still on it. The robot admits that it had been named Macko by the spacer who repaired him. Jeff suggests Norby based on the label (which has now fallen off of him).
- Medals for Everyone: Due to their actions in stopping Ing the Ingrate and his takeover of Manhattan, Admiral Yobo is given a new medal, Officer Jones is given a promotion to Police Lieutenant, Cadet Jeff Wells is given a scholarship and commendation, his older brother Fargo is given a large sum of money to save the family business from bankruptcy, and Norby is made an Honorary Cadet.
- The Nudifier: Fargo Wells once put fabric dissolver into the air conditioning of Neil Armstrong High School. Despite this being many years later, Albany Jones still remembers that day, and the guy who did it to her.
- The Wells family has turned a quote from Scene 1 of Henry V, "The game's afoot" into an initialism; TGAF.
- Norby, a robot made from a barrel of nails, is assumed to be an old R2 model, borrowing from Star Wars and their R2-series astromech droids. He's actually assembled from scrap and a crashed alien spaceship.
- The bird-watchers leader, Miss Higgens, cries out "onward Higgins's soldiers, marching for the right!", a cry based on the 19th-century English hymn, "Onward, Christian Soldiers", a song often sung in demonstrations and civil protests.
- Technobabble: Chapter two explains a few terms that will be showing up in the story as a bit of Narrative Filigree to solidify the story as Science Fiction. Transmit is short for matter transmitter, which can send people from Mars to Earth at the speed of light. Hycoms are short for hyperspacial communications, which provide instantaneous communication. Then there's antigrav; invented fifty years ago and now small enough to fit in your car, providing the ability to float in the air.
- Title Drop: Norby is first called the "mixed-up robot" at the end of chapter four, when Jeff is describing how ignorant, uncertain, confused, and unique he is.
- Two Aliases, One Character: Ing the Ingrate is deceiving everyone by wearing a voice distorter and a mask to prevent people from learning his true identity; Agent Two Gridlow. It isn't revealed until the penultimate chapter, and neither character is on-screen for very long.