[Episode starts with Karai dejectedly trying to use her miniature weapon to get herself out, then Fishface comes with a bowl of food in his hands.]
Karai: Well, if it isn't the sushi I ordered.
[Fishface sighs in annoyance at the insult, nonetheless. He gave Karai some food.]
Karai:[Disgusted.] Ugh, and whatever that is. Can't you lay some masago for me?
Fishface: [Annoyed.] This is a dungeon, not a bed and breakfast. You will eat whatever I bring.
Karai: You mean whatever Tiger Claw tells you to bring.
Fishface: [growls.] If master Shredder didn't need you,[Grabs the bars in anger.] I would teach you some manners.
Karai: Oh, really? And what does he need me for?
Fishface:[Angrily points at Karai.] Just watch your tongue, girl.
[Fishface leaves, irritated. Karai pulls out the bar she has cut out, opens the cage door and is about to escape, but then Tiger Claw grabs her from behind and hurls her on the floor!]
Tiger Claw: Where do you think you're going, little one?
[Karai tries to smack Tiger Claw with bars, but is unsuccessful and is kicked. She kicks back and leaps at Tiger Claw but she is pinned and becomes knocked out cold. Tiger Claw was about to finish her off, only to be stopped by the Shredder.]
Shredder: Stop! You will not harm her.
Tiger Claw: As you wish, Master Shredder.
[Shredder looks at Karai as Tiger Claw gets off from her. Karai wakes up, only to find that she is in a different cell and her hands are handcuffed. Shredder enters.]
Shredder: [calmly] Karai, I wish you could understand.[takes off the mask part of the helmet] Everything I have done is for our clan's honor. Why do you insist on hurting me?
[Karai stays silent, quietly fuming.]
Shredder: [confused] Have you nothing to say to me, daughter?
[Furious upon hearing this, Karai turns around to face Shredder. Her face looks full of rage and then, she harshly berates him, angrily screaming.]
Karai: [angrily] I am not your DAUGHTER!!!
[theme song]
[In the lair, the turtles are planning to save Karai. Leo worked on a plan to rescue Karai from Shredder's lair without getting caught.]
Leo: This is the only way it can work, Raph.
Raph: Yeah, look, I'm on board for the whole "rescue Karai" thing, But if we're going through the trouble of invading Shredder's lair, we gotta take him down once and for all.
Leo: It's too risky.
Mikey: Hold up, dudes. Why do I have to be the bait while Donnie sits in the Shellraiser?
Donnie: Someone's gotta be the getaway driver.
Leo: Look, everyone is important here.
Splinter: Disagreement about a mission is never a good way to begin. Leonardo, may I speak with you? I know you are anxious to free Karai, but a plan that leads to confrontation with the Shredder is doomed to failure.
Leo: Even if we have to face Shredder, isn't it worth it to rescue your own daughter?
Splinter: I am not willing to risk your lives or my daughter's.
Leo: [sighs.] Hai, sensei.
Mikey: So is that a "no go " on operation: Rescue Karai?
Leo: No, Splinter's wrong. We can't wait. Let's do this!
[At Shredder's lair]
Leo: Donnie, you monitor from the Shellraiser and give us some cover. Mikey will distract them with his mad skills. While Shredder's henchmen are distracted, Raph and I sneak in through the sewers.
[Everyone began to do their job, Donnie began to use an electrical fuse. that turns the lights off. Mikey sneaks past to distract. and Leo and Raph battling foot bots in the dungeons. Then they made it to Karai's cage.]
Leo: Karai, it's us.
[Karai looks at the other side.]
Karai: Leo?
[Leo smiles at Karai, who looks quite shocked, then sarcastically looks at him.]
Karai: Took you long enough.
Leo:[flirts with her] Well, we got tired of waiting for you to escape on your own.
Raph: Is this a rescue or a romantic comedy? Come on.
Leo: Just keep an eye out for Foot and Shredder.
[Meanwhile, Mikey is making Shadow Puppets while Razhar and Fishface follow, and get bumped into each other.]
Fishface: It's a trick!
[They managed to get Karai free.]
Leo: Got it. Let's go.
[Leo and Raph begin to leave. Before joining in, Karai takes out the sword from the destroyed Footbot.]
Karai: [confused] How did you get past Tiger Claw?
Tiger Claw: [appears and confronts them] They didn't!
[Raph and Leo charge at him. Tierc Claw kicks Raph as Leo charges at him before being knocked down. Karai leaps over Tiger Claw. Meanwhile, Mikey faces Rahzar and Fishface.]
Mikey: You are looking good, Rahzar. Lost some weight?
[Rahzar lunges and scratches his arm, which causes Mikey to scream in pain in slow motion. Mikey impressively kicks Rahzar to the garbage. While clutching his arm and grunting in pain, Mikey sees Fishface confronting him.]
Fishface: Let's see how well you fight with one arm.
[Fishface attacks Mikey to scratch Mikey's other arm to weaken him. Meanwhile, Donnie checks through the computers to see Leo, Raph and Karai confronted by Tiger Claw.]
Leo: Donnie, we could use the cavalry.
Donnie: On it. I hope this dog whistle works on cats.
[Tiger Claw brutally defeats them, like slamming Leo to the ground, punches Karai to the air and punches Raph away. But suddenly, Donnie uses the dog whistle at the Tiger Claw, which causes him to roar in pain. Raph knocks him down to the ground.]
Karai: This isn't over, Tiger Claw.
[Meanwhile, Mikey dodges Fishface. Fishface attempts to slash Mikey, but succeeds to make Mikey fall. Mikey grabs Fishface by chaining his robotic legs to his nunchaku. They scream and fall. But Mikey realizes that he did not fall. Mikey finally stands up and runs off, leaving Fishface hanging and glaring at Mikey in anger. Raph, Leo and Karai escape and come out of the sewers. Mikey comes along with an injured arm. Raph, Leo and Karai come out of the sewer and see Mikey.]
Raph: Mikey!
Mikey: I'm good. It's not my water-balloon-throwing arm. Ow!
[Leo and Raph take Mikey and are about to escape with Karai, but they are surrounded by the Foot Clan.]
Tiger Claw: Surrender, reptiles. You're outnumbered.
[They were about to be kidnapped, but suddenly dog whistle tortures Tiger Claw again... it is revealed that it came from Donnie, who arrives with the Shellraiser and destroys some foot.]
Donnie: Better count again!
Mikey: Sweet timing, D.
[All leave, except Karai who watches at Shredder, who is at the top of his lair and glares at Karai with an enraged expression on his face, because of her betrayal.]
Leo: [in slow motion.] Karai.
[She goes to the Shellraiser. Foot Soldiers, Tiger Claw and Fishface going after them with motorcycles. In Shellraiser, there is an alarm for bad guys! Raph sees no manhole covers at all and turns to Donnie and Mikey.]
Raph: Okay, who forgot to load the manhole covers?
[Mikey points at Donnie, indicating that he is the one who forgot to load as Donnie watches angrily at Mikey for exposing him as Raph watches at Donnie furiously, with fire from his eyes. They shoot balls of trash at the foot soldiers and motorcycles, mostly defeating them. As Tiger Claw and Fishface use their lasers at them. The purple and red lasers came out as they shot Shellraiser, and we cut to Donnie and Karai.]
Karai: [angry and disappointed] That's all you've got? Balls of trash?!
Raph: This baby's still got a few tricks in her.
[Donnie uses the smoke screen, which unleashes smoke. The smoke blinds the villains, who cough. Then, Donnie uses pizza grease, which black oil comes out and it spills around the road, which causes the villains to crash, except Tigerclaw who uses his jetpack to fly away. Cut back inside, turtles sigh in relief.]
Leo: Not a bad bit of rescuing, huh?
[Karai smiles at Leo, but to her shock, the sword appears... Tiger Claw grabs Karai!]
Leo: Karai!
[Raph tries to catch her, but to no avail.]
Tiger Claw: I have you now.
[Karai tries to defeat him, but Tiger Claw powerfully defeats her and throws her out to her death, but she was saved as Tiger Claw was knocked out cold by how he was bumped by the roof.]
Mikey: Eat that, kitty cat! Whoo-hoo!
[Donnie and Mikey pull Karai back in, both turtles sit down in relief. Feeling very remorseful for her mistreatment to the turtles, Karai glares at them with a very shocked and remorseful expression on her face.]
Karai: Guys. Leo...
Leo: [happy] I know, you're not good at saying thank you.
[Karai smiles at Leo warmly as we cut back to the lair.]
[Mikey sits down, grunting, Raph bandages Mikey's arm, as Donnie drinks from a carton in the background.]
Leo: I hope this means you'll stay. After all, you are family.
Karai: With Shredder after me, what choice do I have? [looks around] It's actually not bad.
Mikey: It's awesome, right? This calls for a family hug. Bring it in. [his arm still hurts]
Splinter:[concerned] Michelangelo, what happened?
Mikey: It's just a scratch, sensei. You should see the other guy.
Splinter: What have you boys done? I thought I told you-[sees Karai] Miwa.
[Karai walks over to Splinter and tearfully hugs Splinter for the first time of her life.]
Karai:[emotionally] Father.
[Splinter hugs her back, with turtles watching happily, with they are now a family.]
Leo:[happily] You see, sensei, I told you my plan would work.
[Karai smiles at her father.]
Splinter:[completely satisfied] Perhaps some things are worth the risk.
[In Shredder's lair, Tiger Claw arrives.]
Tiger Claw: [growls.] I have scoured the city, but I've been unable to sniff out the turtles or Karai. Footbots are still on the search. They will report back to me with every detail.
Shredder: Karai's escape was inevitable. In fact, I was counting on it.
Tiger Claw: Why? She knows everything.
Shredder: Before long, Karai will return with Hamato Yoshi and his wretched turtles to finish what they started, But I will have my vengeance. Get me Baxter Stockman.
[Lightning strikes. Back in the lair, Karai is now living in the lair, trying to adjust to her new lifestyle as a normal daughter of the Hamato, with her father, Splinter and turtles as her adoptive brothers. The turtles are training as Karai and Splinter watch.]
Leo: Come on, Mikey. Focus.
[Leo attacks Mikey, who dodges every attack, then Mikey slaps Leo, which causes an angry turtle to attack his youngest brother and delivers a kick.]
Mikey: Ow, dude!
Leo: Sorry, I didn't [gets splashed by water balloon]
Mikey: Oh, yeah, son! Never underestimate the water balloon arm.
[Leo looks at Karai laughing at him in amusement while Splinter facepalms in dismay and annoyance. Leo blushes in embarrassment, indicating that he has some romantic feelings for Karai, though he disliked her in The Alien Agenda. Enraged with Mikey for embarrassing him in front of Karai, Leo growls in fury and angrily charges at him.]
Mikey: No, no, no, no, dude, wait! Ow, my arm.
[Leo attacks Mikey, but they tumble around onto Donnie. Raph watches confused. He drops his sai, closes his eyes and shrugs (which can say:'Eh, why not') and joins the doggy pile.]
Karai: [curious, but happy] Is this how training always goes?
Splinter: Ya me! My sons and daughter, that is enough for today.
[Turtles bow to their father and leave the dojo to the living room to relax. Leo stops and goes to Karai, who's not turning around to his face, only watching stoically at Splinter.]
Leo: Karai, you coming?
Karai: In a minute.
[Leonardo leaves.]
Splinter: Not what you expected?
Karai: I admit, it's a little weird being with people I was told were my enemies. [looks at the photo] What really happened between you and Shredder and my mother?
Splinter: I'm afraid it goes much deeper than our rivalry over your mother.
[Flashback begins about Miwa's life.]
Splinter: The bitter feud between the Hamato and Foot clans lasted centuries. Oroku Saki was the son of the enemy, but he was just a child, so my father gave him shelter. We were raised as brothers And rivals in all things, as brothers are. But that rivalry soon turned bitter when we met Tang Shen, your mother. Jealousy became hatred when Saki learned of his true heritage. He swore vengeance and rebuilt the Foot clan. One night, Oroku Saki struck. The blow that was meant for me struck your mother instead. Shredder blamed me, and in his rage, he burned our home to the ground, leaving me to my fate.
[End of Flashback.]
Splinter: He took you away from me.
[After Splinter ends, Karai is angered by the lies after all these years, Shredder did to her.]
Karai: After all this time, haven't you wanted revenge?
Splinter: After all this time, I have learned revenge only leads to more pain.
Karai: But I've seen you fight, father. You could take him out.
Splinter: We are safe here, and we are finally together again, my daughter. That is all that matters, not revenge.
[Both daughter and father drink their tea. Cut to the turtles who are sleeping. Leo comes to check on Karai, who's seen sleeping.]
Leo: Karai, are you awake?
[She still sleeps, Leo buys on it and leaves...Karai suddenly opens her eyes, wanting to get her new revenge on Shredder for all the lies she did to her and to avenge her mother's death. She was about to escape, but Leo stops her, indicating that he knows her plans.]
Leo: Going after Shredder alone is a bad idea.
Karai: Don't try to stop me, Leo.
Leo: I want to go with you.
Karai: What?
Leo: You're right. Shredder will never stop hunting us. The only way for us to be safe is to take him down.
Karai: So much of my life has been about revenge. I can't ask you to risk your life too.
Leo: Let me help.
[After a pause, she walks up to him and smiles. There's a long silence. Leo gets incredibly shocked and embarrassed, thinking she is going to kiss him, looks around, before glaring back at her.]
Karai: Sorry, Leo.
[She punches him, then throws a smoke bomb on him, Leo coughs and collapses to the ground, knocked unconscious.]
Karai: This ends tonight!
[Cut to Leo. He awakes and realizes Karai has escaped!]
Leo: Guys! Sensei!
[Splinter and his brothers walk up to him, confused.]
Splinter:[confused] Leonardo, what happened? Where is Karai?
Leo: She's gonna take out Shredder on her own.
[Splinter closes his eyes, realizes he went too far.]
Splinter: [Worried.] I was a fool. I fear I told her too much. Too quickly.
Leo: We have to stop her.
Donnie: We can catch up to her in the Shellraiser.
[Not wanting to lose his daughter once again, Splinter joins his sons in this mission and goes to the Shellraiser. Meanwhile, Karai takes down Footbots, she goes to the throne room, but to her shock, the figure is definitely not Shredder... it's the Chrome Dome! Until the real Shredder arrives.]
Shredder: Karai.
Karai: Shredder.
Shredder: You returned even sooner than I expected.
[Chrome Dome attacks Karai, who tried to kill her, but Karai destroys him by slicing him.]
Karai: The time has come for me to say good-bye, Shredder.
[She starts to attack Shredder but Shredder dodges and grabs her sword.]
Shredder: Foolish child. I taught you everything you know. You hold no surprises for me.
[She throws ninja stars at him but Shredder pins her down.]
Shredder: This has gone far enough.
[The lights turn on as Shredder tossed her to Tiger Claw.]
Tiger Claw: Still no sign of the turtles
Shredder: They can't be far behind. Take her to Stockman. It is time to begin the experiment.
Karai: Let me go!
[Shellraiser arrives as the mutant family sees tons of vans and motorcycles of the Foot. Leo thinks that they are too late.]
Leo: [shocked] They got Karai. We're too late. Raph, fire up the weapons.
[Thinking it would harm his daughter, Splinter quickly stops him.]
Splinter:[objects] No, it's too dangerous. Follow close, but don't let them spot us.
[In Stockman's lair.]
Stockfly: Whatever you require, I can create it. More mutagen, a few chemicals, and some -
Shredder: Stockman.
Stockfly: Aah!
[The fly was startled by an interference of his master, which causes him to drop one of his chemicals in one bottle, which causes his experiments to go wrong.]
Stockfly: Oops. Um, that should be okay. Master Shredder.
Shredder: Is the mutagen ready?
Stockfly: Prepared to your specifications. The serpent DNA is ready.
Karai: No, you wouldn't!
[Tiger Claw gags her with duct tape.]
Shredder: Make sure she is secure.
[Footbots put her to the cage then put her right at the top of the mutagen, thinking that she is going to be mutated! Shredder and Tiger Claw look on.]
Tiger Claw: [stunned] You are more ruthless than I thought, mutating your own cub.
Shredder: I have no intention of mutating her. She is bait. When the turtles attempt to rescue her, I will drop them into the mutagen. This will mutate them into mindless serpents. I want Splinter to witness his own pupils become one of the rat's deadliest predators. Then when his spirit is broken, I will shatter his body.
Tiger Claw: [sniffs and smells something] I smell the rat.
[Taking out his blaster, Tiger Claw shoots the ceiling. There's a silhouette of Splinter. He jumps. His sons join suit. Raph jumps on Stockfly.]
Shredder: Welcome, my old friend.
Splinter: Let my daughter go.
Shredder: You are welcome to rescue her if you can.
[Battle begins with the turtles fighting the Footbots, while their sensei fights the Shredder.]
Shredder: Yes, fight me, rat!
[The Turtles have no trouble fighting Footbots. When Donnie attempts to slash his final Footbot, the latter dodges. As Don backs away, he finds himself trapped in a cage, causing him to drop his weapon. Footbots trap Raph and Mikey into the cages as well. Footbots grab Splinter by throwing the ropes on him. Splinter groans in agony. Leo is the one last turtle in the cage, however, fortunately for him, his sword is not in the cage, and when he uses it to free himself, the cage retracts and he frees himself. Leo goes after Karai.]
Leo: Hang on, Karai.
[Leo comes to the cage and gets the tape off of her mouth.]
Karai: Thanks.
[Leo smiles at Karai, who smiles back... but then Shredder appears from behind!]
Splinter: Leonardo!
[Leo turns around to see Shredder trying to kill Leo by backstabbing, but Leo ducks as Shredder destroys the chains, which causes both of them to fall to the ground, but Karai falls screaming and right into the mutagen.]
Splinter:[horrified] Miwa! Shredder: Karai, NOOO!
[Leo and Donnie (who was still caged) watch in complete horror at Karai's mutation. The cage falls out. Karai slowly comes out of the mutagen and Shredder is seen with great sadness, sheer grief and a lot of genuine remorse.]
Shredder: [remorseful] Karai.
[Karai comes out of the mutagen. She is not a human anymore. She is now a white horned snake, her hands have small snake-like heads. She starts to fall. Splinter frees himself and kills the Footbots and catches his mutated daughter.]
Splinter:[horrified and saddened] Miwa. My child.
[Karai awakens from her mutation, attacks Splinter and destroys the Footbots. Leo and Donnie (who has escaped from his trap, presumably by Leo) destroy the Footbots and free Raph and Mikey. Suddenly, some oil sparks comes out from the Footbots and it engulfs the lair, busting it into flames.]
Stockfly: [laments the destruction of his lab] No, my lab!
[Shredder pushes Stockman away and points accusingly at Splinter.]
Shredder: [enraged] You, Hamato Yoshi! [Furiously draws out his claws.]
[Splinter glares at him with a very furious expression on his face.]
Shredder: [Off screen.] You did this!
[Furious, Shredder growls and screams furiously as he attempts to charge at him, but some pile of rubble crashes to the ground, separating him from his enemy.]
Shredder: No!
Tiger Claw: Master Shredder, we must go.
Shredder: [pushes him, angered] Leave me.
[As Shredder looks around in misery, Tiger Claw attempts to tell him that they have won.]
Tiger Claw: Splinter will suffer for what has happened today. You have won.
[This word visibly hits Shredder, who stands, shocked and speechless, because, now, finally for the first time of his life, thinking that he really was defeated, because now Karai, who loves and cares. With Karai's mutation, Shredder refuses to take this responsibility of forgetting Karai's mutation on his own as he turns to Tiger Claw.]
Shredder: Won?
[Shredder looks at Karai in her mutated form. Karai hisses as he takes off the mask part of his helmet.]
Shredder: I shall avenge you, my daughter.
[Shredder leaves as the rubble separates his way.]
Donnie: We gotta get out of here!
Leo: Not without Karai.
Splinter: Karai, you must listen to me. We must go. [grunts.]
[She grabs and wraps Splinter with her tail, thinking of him as food.]
Splinter: Daughter, please.
Karai:[hisses.] Fa...th...er?
[Splinter smiles, knowing that she still knows him. Karai lets him go, lunges at Raph and spits her venom out to Raph's eyes as Raph lets out a painful scream.]
Leo: Wait!
[Karai slithers away in guilt and sadness as Leo goes after her, while Donnie watches in shock. They all escape Shredder's lair from fire. Leo is saddened by Karai's mutation. Failure hits each and one and other, but mostly Leo and Splinter. Donnie tries to cure Raph's vision.]
Donnie: Easy, Raph.
[Donnie pours some water from a pumpkin at Raph's eyes.]
Raph: [annoyed] Enough! I can see fine now.
[Sirens wail. Depressed, Leo solemnly walks up to his heartbroken master.]
Leo: [sober] This is all my fault. I should've stopped her when I had the chance. I'm sorry, sensei.
[Splinter doesn't respond.]
Leo:[worried] Sensei?
Splinter:[heartbroken] We should go home, my sons.[leaves.]
[Devastated and even saddened by Karai's mutation, turtles look down in defeat and sadness.]
Mikey: [devastated, but hopeful] You can make a retro-mutagen for Karai, right?
Donnie: [dark and soft voice in sadness] I don't know, Mikey. I hope so.
[Everyone leaves sadly back home, but Leo stays for a while with sadness. Elsewhere, Karai is seen changing back into her human form with her eyes still remaining as a serpent's. It reveals that Karai can shape-shift revealing the Stockfly must have added a chemical in the mutagen.]