Bart and Lisa fear that they might have killed Martin while Marge thinks Homer is cheating on his diet.

!! Tropes:

* TheBGrade: Lisa believes telling the truth would be worse that one million "A minuses".
* BrainBleach: Homer "making out" with the food he stuck while in a motel shower.
-->'''Host:''' [[IcantBelieveImSayingThis I can't believe I'm saying this]], but turn the camera off.
* MadeOfIron: Musing about the details of Martin's death, Nelson commented things didn't add. Hearing that, Jimbo, Kearney and Dolph wanted to beat him up for wanting to ''add''. However, he's so tougher than their other victims he not only didn't show any pain but also didn't show any sign he was aware of people hitting him.
* MoodWhiplash: going from a cop talking about a child's death to a children's cartoon
* [[spoiler:NotQuiteDead]]: [[spoiler:Martin survived]].
* PlagiarismInFiction:
-->'''Bart:''' I didn't know there was a national park here.\\
'''Lisa:''' You wrote a report on it last week.\\
'''Bart:''' The internet wrote it. I just handed it in.
* SmarterThanYouLook: Nelson spends half of the episode trying to get Lisa and Bart to confess that they were involved in Martin's disappearance, complete with him inspecting the scene of the "crime" and playing off their paranoia (or at least Lisa's paranoia).
* ShoutOut:
** [[Series/{{Columbo}} Just one more thing...]]
** The ending parodies the opening of ''Series/TheNBCMysteryMovie''.
* TakeThat: Creator/DanielleSteel
* YourCheatingHeart: The show "Sneakers" is made to show an unfaithful spouse/significant other cheating in some way. Marge's plot involves hiring this team to proof that he's cheating on his bell pepper diet and they do it in a way that makes him look like another cheater.