Milo, Zack and Melissa go to school after sunset to retrieve Melissa's math book. Unfortunately, she leaves the spare key inside the locked classroom, so the three go on a "quest" in search of the mysterious janitor, otherwise known as the "key-keeper".
Tropes:
- Air Quotes: Zack uses those when referring to the quest multiple times, but when Melissa uses it in the end, he admits that it was a real quest.
- Bait-and-Switch Comment: When the Principal lends Melissa a spare key, she asks if Melissa, Zack and Milo know what happened to the last kid who borrowed keys from her and didn't return them. They say they don't and the Principal tells them that, if they find out, tell that kid she still wants the key back.
- Bookcase Passage: Played with. Milo tilts a book from the bookcase to see if it would reveal a Secret Underground Passage (it doesn't), but Murphy's Law being Murphy's law, it makes the bookcase fall apart. But part of the wall also falls apart, and that is a secret passage.
- Drama Club: The school has one, as they make a small appearance here.
- Literal Metaphor: Melissa says if Zack doesn't want to be part of the quest there's a chair with his name on it. A girl named Crystal carved his name inside of a heart in the chair.
- Mundane Made Awesome: A simple trip to school to retrieve Melissa's math book is treated as an epic quest.
- Noodle Incident: Milo mentions that The Mona Lisa on display at the Louvre is actually a copy made by his cousin. It's implied that something happened to the original due to Murphy's Law.
- The Quest: Milo and Melissa insists that they're partaking in a quest set up by the school janitor. Zack is initially skeptical, but eventually agrees by the end of the episode.
- Running Gag: Someone appearing from the shadows, but turning out to be someone the trio knows.
- Ship Tease: Zack and Melissa get pretty 'touchy' while teasing each other.
- Skeleton Key Card: Milo opens a locked door using his student ID card.
- Spiders Are Scary: Zack and Melissa freak out a bit when Milo says the spiders they are covered of are real.
- Take That!: To student ID cards. Before Milo uses one as a skeleton key card, Melissa doesn't know what the cards are useful for.
