With Leonardo gone, the Turtles and Splinter ended up getting into a fight with Karai, who has become the new Shredder and bent on killing them for putting the Shredder in exile on the icy asteroid since "Exodus Part 2".
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!!This episode provides examples of

* AllYourBaseAreBelongToUs/ WatchingTroyBurn: Karai and the Foot [[TrashTheSet completely destroy]] the Turtle's Lair, and there's [[WatchingTroyBurn nothing they can do to stop them]].
* AmbiguousSituation: Donnie asks how the Foot found them, but Raph succinctly points out it doesn’t matter given they‘ve already found them. It’s never outright confirmed, but the Foot Mystics did find the Turtles and Splinter in “Bad Day”, potentially being the culprit.
* AvengingTheVillain: Karai's motivation for attacking the Turtles
* TheBadGuyWins: At the end of the episode it looks like Karai's succeeded in killing most of the Turtles and Master Splinter
* BerserkButton: After getting some snark:
-->'''Karai:''' You mock me. The fact you still live mocks me!
* BigWhat: Leonardo when the Ancient One warns him that his family is in danger.
* CallBack: Mikey making the extra effort to save Klunk is a sly reference to "Bad Day" (where Klunk died during the mystical illusion).
* ContinuityNod:
** Mikey hopefully asks if this is [[Recap/TeenageMutantNinjaTurtles2003S4E8BadDay another mystical attack]]. Splinter briefly pauses, clearly considering the idea, but ultimately tells him this is real.
** Mikey was apparently still keeping his Battle Nexus trophy [[Recap/TeenageMutantNinjaTurtles2003S4E6GrudgeMatch on top of the TV]].
** While facing Splinter, Karai recalls how [[Recap/TeenageMutantNinjaTurtles2003S3E25ExodusPart1 she begged Leo to let her father go]].
* CurbStompBattle: With the Turtles and Splinter only given a precious few seconds warning and the Foot clearly having done their research on everything they had access to, the family is almost immediately put on the back foot and are ultimately forced to abandon their home.
* DownerBeginning: The episode opens with the remaining turtles and Splinter clearly despondent over Leo's absence.
* DownerEnding: The Turtles (except Leo) and Splinter are presumed dead by Karai's hands.
* DragonAscendant: Karai reveals she has taken on the mantle of the Shredder.
* DramaPreservingHandicap: Happens to Splinter, Don and Mike:
** Master Splinter is injured by Karai and he spends the rest of the fight out of commission.
** Don has to carry Master Splinter over his shoulder, supporting him with both his arms, leaving him unable to use them and his weapon, forcing him to rely on kicks alone to combat his opponents.
** Mike is carrying Klunk, who is a tiny kitten and can fit in his hand. So, at any given point, while he is not completely handicapped, like Don, he is still unable to give his 100% in a fight.
* DreamingOfThingsToCome: During meditation, the Ancient One foresees the Shredder's gauntlet. He warns Leonardo that his family is in danger and that he must return home at once.
* EtTuBrute: Splinter doesn't hold back at all with his furious disappointment that Karai has completely abandoned her respect and honor to his family.
* EvilLaugh: Karai has one when she believes she is winning and finally getting rid of the Turtles for good.
* FallOfTheHouseOfCards: Occurs to Mikey early in the episode. It symbolizes [[RuleOfSymbolism how the Turtles will soon lose their home]].
* IRejectYourReality: Splinter accuses Karai of being blind to the reality of how cruel and dishonorable the Shredder was, especially when she refuses to believe that Oroku Saki murdered Hamato Yoshi and dismisses Splinter's claims as lies.
* KickTheDog: Besides losing their home, the attack also costs the Turtles and Splinter some of their most precious possessions. In particular, Karai waits until Splinter runs to retrieve Master Yoshi's orb before cruelly smashing it in front of him. She also rubs her victory in April's face.
* KindHeartedCatLover: Mikey doesn't leave the lair [[NoOneGetsLeftBehind until he finds Klunk]].
-->"I got ya, pal!"
* LetsSplitUpGang: When the Turtles are getting overwhelmed by Karai's forces, and Master Splinter is injured, they decide to split up to maximize their chances of getting away.
* LightningBruiser: Karai is even faster than her father, as Splinter begrudgingly admits.
* {{Mouthscreen}}: Karai
* NumberTwo: In Leo's absence, Raph gives the order to fight the Foot, then to split up and leave when Splinter gets injured and they're clearly overwhelmed. Interestingly, Don seems to catch onto them being overwhelmed well before this point, but rather than try to give the order himself, he prompts Raph ''twice'' that there are too many Foot ninjas and that "they need to get out of there" to push ''him'' to make a decision.
* OffhandBackhand: Splinter takes out a Foot Ninja behind him with his cane without even looking.
** Earlier, Don took out a foot ninja approaching him from behind by elbowing him in the gut without looking, while simultaneously fighting two more foot ninjas.
* OhCrap:
** Raph's reaction to "Shredder" (now Karai) walking into their lair.
** Also April after Karai explains her message for Leo and leaves the dented "Sewer Sweet Sewer" sign on the counter.
* OpenMouthInsertFoot: Donnie, forgetting Leo was gone, tells Raph to "ask Leo" his question, only to realize his gaffe when everyone in the room lapses into a sad silence.
* OurHeroIsDead: The episode ends with Donatello, Michelangelo, Raphael, ''and'' Splinter all [[UncertainDoom seemingly]] [[NeverSayDie destroyed]].
* PunctuatedForEmphasis: While fighting off the Foot Ninja, Raphael angrily says with each blow "[[GetOut Get! Out! Of! My! HOUSE!]]".
* TheReasonYouSuckSpeech: Splinter lays into Karai for becoming the new Shredder and ''snarls'' that her dark heart will consume her, just as her father's did.
* RevengeBeforeReason: Karai. Splinter even calls her on it.
* RoaringRampageOfRevenge: Karai.
* ThisCannotBe: The group is understandably horrified that their home has been discovered by the Foot, and Donnie is particularly alarmed when their perimeter alarm is cut off.
-->'''Donnie:''' But ''how?!'' How did they find us?!
* ThisIsGonnaSuck: Donatello when the perimeter alarm goes off and then suddenly cuts out. It's designed to keep ringing until manually turned off, so he knows it means trouble is about to come knocking.
* TookALevelInBadass: The Turtles remark that the Foot are ''much'' tougher now under Karai's leadership. Raph is left exhausted after being trapped in the elevator to the garage with just three Foot soldiers.
* TrashTheSet: Karai orders the Foot to "tear this filthy place [the Lair] apart". They do.
* VillainBall: After taking care of Splinter, Don, Raph and Mike, the Foot ninjas don't even bother checking for bodies or proof that they actually are dead, a mistake Oroku Saki/Ch'rell tried to avoid [[Recap/TeenageMutantNinjaTurtles2003S1E19TalesOfLeo earlier]] (and even then, it didn't work only because [[TheStarscream Baxter Stockman]] screwed him over with false evidence). As the following episode reveals, this results in all of them surviving.
* VillainousLegacy: Ch'rell the Utrom might be trapped among the stars[[note]][[WesternAnimation/TurtlesForever For now]][[/note]], but his daughter Karai has now taken up the mantle of the Shredder.
* WhamEpisode: The Turtles' Lair, that they’ve lived in since the middle of season one, is destroyed, and the group is scattered to the winds, having lost many sentimental items such as [[{{Tearjerker}} Yoshi's orb]], Mikey's Battle Nexus trophy, and most of the Turtles' vehicles - all thanks to Karai's ascension to become the new Shredder.
* WhamShot: The Shredder appears entering the lair. However, this one removes ''her'' helmet to reveal she is Karai, taking the legacy of her adopted father.
* YouCantGoHomeAgain: The lair is destroyed with its location having been uncovered. What’s worse is that every step the Turtles take to try to escape, the Foot are onto them. Not even their garage is safe, as Raph finds the Foot waiting for them.
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