Drakken and Shego invade the lab of Cyrus Bortle (from [[Recap/KimPossibleS1E17TheTwinFactor "The Twin Factor"]]) to steal an "Electron Magneto Accelerator". They are interrupted by Team Possible, but manage to escape with the EMA. However, during the fight both Kim and Shego got [[EmotionBomb emotion-controlling "Moodulator" chips]] attached to them without anyone noticing. Also, Ron accidentally picks up the Moodulator control unit, mistaking it for the Kimmunicator.
After Kim notices that the device they have isn't the Kimmunicator, Ron mistakes it for a video game and starts playing with it. This causes both Kim and Shego to start [[MoodSwinger rapidly shifting moods]], from sadness to giddiness to rage. Ron and Drakken, having no idea what's going on, find themselves bearing the brunt of their odd behavior. [[HilarityEnsues The sitch escalates]] when the control unit gets set to "love", causing Kim and Shego to start aggressively pursuing their partners, much to their discomfort.
!!This episode provides examples of:
* EmotionBomb: The Moodulator chips and their control unit.
* IBrokeANail: Shego cries uncontrollably over a broken nail while the Moodulator is set to "sad".
* IWantMyMommy: Drakken whimpers "Mommy" when confronted with a Moodulator-enraged Shego.
* IfYouEverDoAnythingToHurtHer: [[OverprotectiveDad Kim's dad]] [[TwerpSweating warns Ron]] that he'd better not make Kim unhappy unless he wants a one-way trip to a black hole. Considering Kim's dad is a rocket scientist, ''that is not an idle threat.''
* IKnowYoureInThereSomewhereFight: Ron tries to jog Kim's memory of "the good times" as she tries to hurt him.
* InsistentTerminology: Drakken prefers to think of stealing another scientist's invention as "Outsourcing".
* JuxtaposedHalvesShot: A brief montage of Kim and Shego going through a range of emotions ends with a half-and-half closeup of their "enraged" expressions.
* KissingUnderTheInfluence: The "lovestruck" Kim (under the moodulator's influence) has her first kiss with Ron.
** Shego is under the influence of the same device. In defiance of the usual "one-sided case" variation, Dr. Drakken spends the entire episode weirded out by Shego's mood swings and terrified by her actions when it's set to "very angry". The two only get an implied kiss.
* LittleBlackDress: Kim's outfit for her date with Ron. It makes [[JawDrop quite an impression]] on him.
* LetsJustBeFriends: Despite Kim for all intents and purposes seeming to be totally in love with Ron, and Ron even admitting he has thought about having a romantic relationship with Kim he doesn't want to ruin his lifelong friendship with her and gives her one of these speeches. Too bad it's at that moment the moodulator switches from love to sadness and Kim seems to take Ron's refusal very hard.
* MistakenForSpies: Cyrus Bortel mistook the left behind Kimmunicator for a spy drone (which actually it was, but wasn't spying on ''him'') and when he caught up to Ron at the climax of the episode, he called him a spy.
* MoodSwinger: Kim and Shego wildly switch moods when Ron fiddles with the Moodulator control unit (which he initially thinks is a video game).
* OffscreenTeleportation: When Kim is in "lovestruck" mode, she keeps popping up wherever Ron is in spite of his efforts to evade her.
* OhCrap: Drakken has a whiplash mood shift of his own when he goes from gloating about Kim being trapped in "an irreversible frenzy of rage" to realizing (when he hears that there were ''two'' Moodulator chips) that Shego is likewise frenzied with rage, directed at him.
-->'''Drakken''': A scorned woman! ''[[EvilLaugh HAHAHA!]]'' The perfect weapon!
-->'''Dr. Cyrus Bortel''': If she's wearing Moodulator #1, then where is the second one?
-->'''Drakken''': The ''second'' one? [[OhCrap Uh-oh...]]
* PhotoBoothMontage: Shego gets Drakken into a photo booth. The audience sees the resulting pictures, concluding with one of her [[TheGlomp pouncing on him]].
* PostKissCatatonia: Ron is in a daze after Kim (under Moodulator influence) kisses him.
* ShipSinking: Subverted. When the episode first aired, many were lead to believe that Kim and Ron would not have a romantic relationship...then along came ''[[WesternAnimation/KimPossibleMovieSoTheDrama So The Drama]]''.
* ShipTease: Both Kim/Ron (before they became an OfficialCouple in ''[[WesternAnimation/KimPossibleMovieSoTheDrama So the Drama]]'') and Drakken/Shego (before the implied LastMinuteHookup in ''[[Recap/KimPossibleS4E22Graduation Graduation, Part 2]]'').
* ShoutOut: Angry!Kim tells Ron that he's "[[Series/ILoveLucy got some splainin' to do]]!"
* SpitTake: Wade does this and falls off the chair when he sees Romantic!Kim & Ron kissing each other.
* StalkerWithACrush: Kim and Shego act like this toward Ron and Drakken, respectively, when the Moodulators get set to "love".
* SweetieGraffiti: Shego blasts a heart with "D.D. & SG" into the wall of the lair. Drakken gets even more thoroughly creeped out.
* TrickDialogue: After a montage scene of Ron expressing [[IDontWantToRuinOurFriendship his concerns]] about [[RelationshipUpgrade going from "friend" to "boyfriend"]], we find out that he's been talking to Mr. Barkin.
-->'''Barkin:''' Stoppable, how did you get in my house?!
* TroubledFetalPosition: Drakken curls up and sucks his thumb after dealing with Shego's [[MoodSwinger wild emotional shifts]], including rage.
-->'''Drakken''': Did I [[ForgottenBirthday forget your birthday]]? Is that what this is about? Because... I'm scared.
* UnstoppableRage: Dr. Bortle calls it "irreversible frenzy of rage", but Rage!Kim and Shego spend several minutes relentlessly pursuing the terrified Ron and Drakken.
* WomanScorned: When the Moodulator control gets broken while set to "rage", Kim (who had gotten a LetsJustBeFriends talk from Ron) and Shego (who Drakken had abandoned in the middle of a crying jag to carry out his evil scheme) start taking out their anger on their respective male partners.