Spinelli gets annoyed when TJ and Vince start reading mystery novels during recess. She says recess is the time to play, not be suspicious of every seemingly little clue. Then a new janitor shows up, filling in for Hank while he is on vacation. TJ and Vince try to solve a mystery just like the Barnaby Boys by investigating the janitor.
Tropes:
- Blatant Lies: Caught with the statue head and tied up children, Earl brazenly lies to the authorities by saying this is not what it looks like.
- Both Sides Have a Point: Spinelli has her reasons to be annoyed with TJ and Vince for wanting to pursue a mystery. She says that one, real-life doesn't have kid-friendly villains that wait for kid detectives to come and bust them, meaning it's actually really dangerous and that it's cutting into their fun recess time. On the other hand, TJ and Vince were correct that the substitute janitor was hiding something, and end up uncovering a huge crime.
- Chekhov's Gun: Spinelli mentions how the police were never able solve who stole the head of Thomas Jefferson's statue 30 years prior the events of the episode. This plays a key in the episode.
- Chekhov's Gunman: Earl Raymond, the substitute janitor who has filled in for Hank while the latter is in Bermuda, turns out to have swiped the head off of Thomas Jefferson's statue.
- Comically Small Demand: The first time the head was stolen, the culprit demanded $10 and a head start. This time, the demand is 30 times that.Mikey: Whoa, that's nearly $300!
- Expy: The Barnaby Boys are this to The Hardy Boys.
- Friend to All Children: Believe it or not, Miss Finster was one, as shown in a 1966 yearbook photo that also shows what appears to be a young Miss Grotke. Of course, TJ dismisses it as a misprint.
- Genre Blindness: For all TJ and Vince's love of the Barnaby Boys and emulating of their actions, Spinelli points out they didn't follow a key item of the books: calling the authorities before going into a dangerous location.
- Hidden Depths: Spinelli has "casually glanced" at 64 volumes of the Barnaby Boys' adventures.
- O.O.C. Is Serious Business: Gretchen opens the episode by commenting that TJ and Vince have shrugged off playtime for reading mystery books.
- Police Are Useless: Subverted. Spinelli was right to call the school police, who lose no time in arresting Earl Raymond before he can play the Karma Houdini.
- Properly Paranoid: TJ and Vince are suspicious of Earl Raymond, despite Spinelli's objections. They turn out to be right when it is revealed that Earl is one who stole the head off Thomas Jefferson's statue.
- Red Herring: The kids find a piece of paper in Raymond's file with the numbers 19-16-25, which Gretchen decodes with their corresponding letters of the alphabet as the word "spy." As it turns out, it's really a locker combination.
- Wrong Genre Savvy: Due to reading so many Barnaby Boys novels, TJ and Vince spend most of the episode convinced they're in a crime novel themselves. Gretchen points out that solving mysteries is a difficult task, while Spinelli states that "real-life isn't like a Barnaby Boys book." Namely, many kid detectives would be dead or tied up while the villains escape if they didn't call the cops.
- You Meddling Kids: Earl actually says, "I would have gotten away with it too if it weren't for you meddling kids."
