First published by Janet Asimov and Isaac Asimov in 1984, this Science Fiction Adventure story is the second story in The Norby Chronicles.
Admiral Yobo has come to the Wells residence to talk to Jeff about the Inventors Guild wanting to study Norby. While attempting to hide from the admiral and the Guild, Norby finds himself drawn to planet Jamyn. What does the strange planet of dragons and robots have to do with Norby and his inexplicable ability to travel in time?
Norby's Other Secret contains examples of the following tropes:
- Accidental Time Travel: This story introduces Norby's Time Travel ability, but because he's so mixed-up he can't control his built-in abilities, the initial trips, such as the Roman Coliseum and the Ice Age, happen without his intent and they have to figure out how to control it so that they wind up back home in the right time, not just place.
- Dead Guy Junior: A Downplayed example; at the end of the book, when Jeff is given Oola's egg, he decides that he'll name it Oola Two. But Oola is still alive and he hardly ever mentions the Two part, simply calling her Oola in future books.
- Dedication: The start of the book dedicates this to "the beautiful generation", including Patti, Leslie, Nanette, and their daughter Robyn Asimov.
- "Eureka!" Moment: In chapter six, while Norby and Fargo are racking their brains to figure out how to open the hassock, Jeff suggests they take a break by singing a few songs. Fargo calls him a genius and starts laughing, leaving Norby to explain that Fargo now thinks the numbers they'd deciphered stand for musical notes.
- Fun with Acronyms: TGAF shows up in the first chapter, allowing Jeff to communicate to Fargo that the Admiral isn't there for a social call like he claims to be. After the call, Jeff explains to Admiral Yobo that the words stand for "The Game's A-Foot".
- Future Food Is Artificial: The family scout ship has an Auto-Kitchen that can serve a combination of real and artificial food. In chapter six, Jeff gets a meal of synthoburger, synthofries, and reconstituted applesauce.
- Language Barrier: In the previous book, one of the dragons bit Jeff, and in the interim he's adapted to the Jamyn language. This leads to dragons biting new humans, such as Yobo and Fargo, in order to Avert this trope.
- Mind Probe: The prison that Mentor First sticks Jeff in is designed to telepathically extract information, and can be used to torture, but is also used by First when he has bouts of dementia to prevent him from hurting people. It can keep people/robots paralyzed until the computer is ordered to release them.
- Personality Chip: One of the things that Admiral Yobo thinks the Inventors Guild would really like to understand is how Norby, a Robot Buddy, can demonstrate emotions, like shame, pride, loyalty, and fear. Human-made robots appear dumb because they don't have the ability to recite poems or critique William Shakespeare. This ability in robots to feel emotions is based on the assumption of an "emotive chip".
- Psychic Static: In chapter four, when Jeff is placed inside a Mind Probe, he quotes William Shakespeare speeches to generate a shield against the robot's attempt to read his mind.
- Shout-Out:
- Instead of monitoring the kitchen computer, Norby is reading and reciting from Julius Caesar; “Friends, Romans, countrymen, lend me your ears; I come to bury Caesar, not to praise him."
- When placed inside the Mind Probe, Jeff copies Norby's quotation, and goes on to quote several other William Shakespeare speeches to generate a shield against the robot's attempt to read his mind.
- Single-Task Robot: The gardening robots that Jeff sees outside of the Mentor's castle are dented and discolored from years of neglect. They're specialized in taking care of the landscape, so they don't need to be intelligent, but it adds to the general inhuman nature of the planet to see such strange robots.
- Space Pirates: In chapter 11, the Wells brothers have to deal with members of the Inventors Union who have gone pirate and are trying to salvage/steal the crashed ship of the Others (aliens who visited Earth during the last Ice Age and established the Mentors on Jamyn thousands of years ago) which was supposed to resupply the Jamyn Mentors. Fargo distracts them while Norby steals their ship and contacts Space Command.
- Speak in Unison: When Norby starts to get confused on how to describe when they are in chapter 8, Jeff and Fargo announce they understand what he means to say in unison.
- They Would Cut You Up: Mentioned briefly in the previous book, Norby is concerned that if his unusual abilities became public knowledge, he'd be taken apart and inadvertently killed. Admiral Yobo coming to the Wells household, announcing that the Inventors Union wants to do just that, kicks off the plot of this book, which ends with the admiral convinced that Norby is too unreliable to be studied productively, as well as getting an miniaturized antigrav belt for them to study instead.
- Time-Travel Tense Trouble: Norby and Jeff get mixed up on "before" and "after" when it comes to personal history versus objective history, but both times it gets handwaved away with the other people in the conversation saying that they understood the intent and to get on with the explanation.
- Title Drop: Admiral Yobo has made it clear that Norby's secret, hyperdrive, is something that Space Command needs to learn, even if they have to take Norby apart to figure out the secret. Then he's informed about Norby' other secret; Time Travel. Between a plain mini-antigrav device and Norby's inability to control his time travel, the admiral agrees to make sure everyone leaves Norby alone.
- Tragic Villain: Mentor First is a vaillinous figure; an inhuman robot who attempts to capture and Mind Probe the protagonists. But during one of his saner moments in chapter 10, he reveals that this is because he is so old and broken that he needs to be contained to protect himself and others from his violent impulses. He built a spaceship named Searcher designed to refuel in hyperspace and find the re-supply ship promised by the Others. His demi-dementia causes paranoia and selfishness, making him at times antagonistic towards the Terrans.
- The Unpronounceable: Zargl is fairly pronounceable, as Jamyn dragon names go, but her mother's name is Ziphyzggtmtizm. Jeff asks if he can just call her Zi, which she accepts.
- Uplifted Animal: The protagonists go back in time to see a prehistoric Jamyn, where the resident dragons are unintelligent and only have four limbs. Mentor First claims that the Others have left instructions for them to re-engineer the dominant species into an intelligent civilization.
