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.
* CrazyPrepared: Martin survived falling off a cliff because of a preference to wear a special anti-wedgie set of briefs with extra-extendable elastics (which got caught on a branch as he fell).
* GirlySkirtTwirl: Martin does one when he's showcasing the modesty skirt he sewed by hand with leaves (and took him most of the week he was gone -- it took him ''one hour'' to make a raft to get out of the island he was in). Nelson gives him a DopeSlap as a result.
* KidDetective: Nelson, in full-blown ''Series/{{Columbo}}'' homage mode.
* ItsAllAboutMe: Both Lisa and Bart are concerned about being nailed for Martin's "murder" but Lisa is the one that constantly acts like being on the verge of a nervous breakdown because she can't stop thinking of her possibly shattered future (and her ImagineSpot where she's in prison shows a newspaper cut-out that puts most of the blame on Bart).
* MacGyvering: Martin, as a result of the events that made people believe he died, landed on a small island in the middle of a lake. It took him just ''one hour'' to make a raft to get out... and the week it took for the whole mess to occur for him to sew a skirt out of leaves.
* 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
* NotQuiteDead: Martin survived. It took him a week to get back to civilization because of his SkewedPriorities.
* NoWarrantNoProblem: As befits a ''Series/{{Columbo}}'' homage, Nelson's plan to try to catch Lisa and Bart is to constantly pester them in an attempt to trigger a ParanoiaGambit.
* 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''.
** The episode's title alludes to ''Film/DialMForMurder''.
* SkewedPriorities:
** Lisa's ImagineSpot of herself in prison for helping with Martin's death has the newspaper headlines "Bart killed Martin" and "Lisa helped". The one about Lisa has a bigger font.
** Martin is believed dead for a whole week because he decided it was more important to finish sewing a modesty skirt (by hand, made of leaves) than immediately use the raft he made in ''one hour'' to escape the island he was trapped in.
* TakeThat:
** Creator/DanielleSteel novels are the only books available in prison. It makes Lisa (who is daydreaming of becoming a lifer as a result of Martin's accidental death) bellow out a BigNo.
** "Sneakers" is a regular Fox Network reality show, more concerned about ratings-raising family-destroying schadenfreude than actually helping people. When Marge points it out and acts like a sweetheart with Homer, the host says that it's nice... and if she'll excuse him, he's going to go to the editing room to do some ManipulativeEditing that will make her look like a psychotic WomanScorned.
* 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 prove that he's cheating on his bell pepper diet and they do it in a way that makes him look like another cheater.