Something strange is happening in Nutwood — everyone, including Rupert, and especially the Professor, is forgetting things. Someone's been tampering with Nutwood's files at the Memory Bank — the place where all memories are stored. Rupert, Bill, and the Professor set off to find out what's going on, but their mission is complicated by Bill being trapped in a hand mirrornote by an invention the Professor can't remember how to work, and a strange man from the Professor's past (whom, of course, he can't remember) following them and trying to sabotage them at every turn.
This episode provides examples of:
- Amnesia Episode: Features a widespread plague of amnesia to varying degrees.
- Bag of Holding: The Boolean Box is a "matter compactor" — when the door is closed and it's turned on, it stores everything (and everyone) placed inside it in a hand mirror.
- Cursed with Awesome: Bill's new small, flat, portable form allows him to help the heroes out of just about every jam they get stuck in thanks to Dennis.
- Drowning Pit: Dennis floods the underground tunnel the heroes are passing through in a tram car.
- Evil Former Friend: The Professor and Dennis Finch were partners, until Dennis quit, finding science to be too frustrating to be worth putting in the work. When the Professor continued and became a success, Dennis became jealous and sought revenge.
- Fair-Weather Friend: Dennis abandoned his partner because the work became harder than he liked.
- Glory Hound: Dennis wanted to be recognized as a famous scientist... without being forced to put in all that annoying hard work, study, and research.
- Inside Job: Dennis gets a job as a Memory Bank Examiner so he could steal the Professor's memories.
- "Just So" Story: How do we remember things, and why do we forget things?
- Laser-Guided Amnesia: Unfortunately for those in the vicinity of the target, the villain wasn't too careful with his aim.
- Literally Shattered Lives: Discussed Trope — Bill is understandably very concerned about what would happen to him if someone breaks the mirror he’s stuck in.
- Locked in a Room: Dennis locks the heroes in the Memory Bank vault.
- Memory Jar: The Memory Bank. The memories are written on sheets of paper stored in filing cabinets. When a person's files are removed, the person forgets those memories.
- Mr. Exposition: The Wise Old Goat explains to Rupert and co. (and the audience) what the Memory Bank is and how it works.
- Note to Self: As a precaution against the threat they're all currently dealing with, Rupert spends the episode writing down everything they need to do every time a new task comes up.
- Possession Implies Mastery: Defied Trope — Dennis assumes he can operate the Boolean Box just fine simply by using the plans to build his own. He and everyone at the Symposium quickly learn he has no idea what he's doing.
- Safecracking: To escape the Memory Bank vault, the teller uses a (conveniently found) crowbar to pry away a panel on the door so they can reach the lock mechanism from the inside.
- Sealed Good in a Can: Poor Bill spends the episode trapped in a mirror. At least he can still see everything and communicate with everyone.
- Stealing the Credit: Dennis gave up working on the Boolean Box — the Professor finished it alone. Nonetheless, Dennis intends to erase his memories, steal his plans, and pass the invention off as entirely his own work.
- Strange Secret Entrance: Fortunately, an entrance to the "secret underground station" for the tram car that leads to the Memory Bank just happens to be under the Wise Old Goat's castle.
- Transferable Memory: Memories can be stolen or misfiled in someone else's "account."
- Weapons That Suck: When turned all the way up, the Boolean Box can suck everything nearby inside it.
