[As we continue on to the next episode, April Casey the turtles and everyone we saw buried Splinter in April's farm, where the Kraang invasion started in season 3, pay their final respects at Splinter's grave. Then, one by one, everyone walks away excluding the four Turtles. Leo is the last one to leave.]
[Wandering alone in the woods near the farmhouse, Leo is calmly meditating at a riverbank. The wind whistles and then a voice spoke]
[Leo gasps, revealing that it was Splinter's Spirit.]
Splinter's Spirit:Do not fear me, my son.
Leo:[gasps.]Splinter? Is it really you? Or or am I dreaming this?
Splinter's Spirit:You are not dreaming.I have attained a higher spiritual plane of existence. Passing into death, we merge with the whole of life. We become one in all of nature, in all of the Universe. Even with you.
Leo:I.. I can't go on without you, Father.
Splinter's Spirit:You must, Leonardo. You are the sensei now. Your brothers need you. Karai needs you. Shredder is still alive.
Splinter's Spirit:You must end this, Leonardo.
Leo:I don't know if we're strong enough, Sensei.Sensei? [He was gone.]
[As the wind whistles again, Leo watches some flower petals fly over his head and soar up towards the shining sun breaking through the clouds, before putting on his empty, white eyes,.glowing like a heart.]
[At the hospital, Karai awakens to see everyone.]
Mikey:Karai? Karai, are you awake?
Raph:Wow, you've seen better days, that's for sure.
Karai:I could take you, Raph, even with a broken arm.
Donnie:How you doing, Karai?
Karai: He's gone, isn't he? I had a dream that Splinter's gone.
Leo:Yes, Karai, I'm so sorry.
Raph:We Karai, listen, um, Shredder is still alive. Slash told us that you know where his lair is.
Karai:! wanted to help bring him down.
Mikey:We need to know, Karai, before Super Shredder comes after you. Or April's dad. Or Casey's family.
Karai:It's 20 miles north of here. And Leo? Give Shredder a couple of hits from me.
[Everyone started gearing up for battle. The turtles now wore their shinobi masks on.]
Leo:Okay, based on Karai's intel, Shredder has a secret mansion in the middle of the woods right here. It's heavily fortified, and there are traps and Footbots everywhere. We'll have to keep on our toes.
Mikey:Some of us only have three toes, so, I hope that's cool.
Casey:Eh, five toes are way doper.
Mikey:What if we had six? Ugh! Hey!
Raph: Let's take Shredder down.
Leo:This is it, team. Shredder's mansion is just beyond these woods. Be careful.
Mikey:Ha! These things are a slice of cake and easy as pie.Mmm, so hungry.
Raph:Yeah, at this rate, we've got no problemo.
Donnie: Huh? One of us had to say something, didn't they?
all: Ahh! [water splashes.]
Mikey:Yes! Ah, nice. I love water!
Fishface:Do not call me that! Welcome, tartarugas. I will slap you like a salamander! I will fin you like a flounder! I will give you bass to mouth! [splashing.]
Leo: After him! - [gasps.]
[Fishface:You think you have the best of me? You are nothing, Raphae - Oof!:You dirty scoundrel! [gasping and groaning.]
Stockfly:Hgleh! Fools, there izz nothing you can do against the Super Shredder! He izz perfection itzzelf. My boy Shredder izz going to make you...
Mikey:Eat retro-mutagen, Buxton Bugbrain!
Stockfly:Bzz, it's Baxter, you Huh? No, no, bzz, no!
[He gets hit by the retro mutagen and he became a human again.]
Stockman:I'm.. I'm human again? You turned me back?
Mikey:Yeah, dude! Are you happy or what?
Stockman:You... jerk! I liked being a fly. Why do you think I never demutated myself? Sure, I was super disgusting, but I was smarter, faster, stronger. People liked me as a bug! You morons, I oughta-
Donnie:Michel, that retro-mutagen was for Super Shredder.I only have one dose left now, thanks!
Mikey: Sorry, D. But he didn't even say thank you! How ungrateful can you be?
April:Super Shredder's close by. I can feel him. Let's make our way up.
Bebop:Aww, look at this.They think they're entering the Dragon. Whoo-hoo! Yeah! Turtles be tripping! You seriously think you can sneak up in our house? This is our house!
Casey:Oh, great. Figures Bacon and Bonehead would be here.
Rocksteady:Hey, we are the Bebop and the Rocksteady, not the Bacons and the Bonehead!
Bebop:Shut up, Bonehead! Check it out, Turtles: our state-of-the-art super dope training facility. And guess what? It's programmed to eliminate freaky-deaky Turtles like you!
Rocksteady: Da, and tiny teenage human friends. Ya! Let us crank the puppy up to 11, shall we? ] No fair! My ears be sensitive!
Donnie:Gotta hack the system!
April: Can you hack a little faster, D?
Donnie:Almost got it..Yes! How about a little training session, B&R?
Bebop: Whoo-hoo, I'm outtie 5000. Ooh, sham on, sham on.
Raph:Wow, Tigerclaw! Liking the new steel paw look.Pretty cool!
Tigerclaw:Do not mock me, Turtle. As punishment, I'll take all of your hands.
Tigerclaw:Do you feel it, boy? The weight of the world crushing you, now that your sensei is gone?
Leo: You dirty cat! [roars.]You just used your ninth life, pussy cat!
Tigerclaw:Beautiful, are they not? A tiger can eat 50 pounds of meat in a night.
Raph: Run! - April, some kind of mind-thingy?
April:Yeah, good call. I can't hold it any longer, guys!
Tigerclaw:What my rocket! [rocket powers down.]
Raph:Let's finish this.
Leo:Your time is up, Shredder.
S Shredder:I was wrong. I thought after the death of your master that you would flee from the city as you did before. Afraid to face me. Afraid to embrace your fate.
Raph:Don't flatter yourself, Freak-Nut.
Mikey:MYeah! You're not so tough, Cheese Grater! We got you.
Donnie:Tonight, it ends.
Donnie:The retro-mutagen has no effect!
Donnie:Thanks, April. Better get back up there.
April:Hold up, D. The fire's getting out of control! And I don't have the strength to levitate you.
S. Shredder:Pathetic. Redundant.
Raph: I'm done with you, ya metal freak!
Leo:You killed him. He was your brother, and you killed him! He was your brother, Saki. Your best friend! How could you do that?
S. Shredder:Splinter was cursed to become a loathsome rat! - It was his fate, his destiny!
Leo: You're a monster! A demon! Is that your destiny?
S Shredder:No I I'm-
S. Shredder:And now you die.
Splinter:Leonardo Fear nothing.
[Leo's eyes became white and he finally dodge the attack. and delivers a powerful fatal strike at Super Shredder]
Casey:I can't believe it.
Raph: He's gone?
Mikey: No.No, he can't be! Leo!
Leo:Shredder is finished.
[He drops the broken helmet down. Later on Karai was on the Rooftops until Leo came]
Leo:Karai, I'm so sorry.
Karai:There's nothing to be sorry about, Leo. I just wanted to thank you for finishing what no one else could.
[His brothers approach.]
Raph:You did it, brother. You ended the Shredder.
Leo: Nn! Okay, okay, don't squeeze me so hard, Raph. I'm still recovering.
Donnie:So what are we gonna do next?
April:Oh, I'm sure there'll be plenty of enemies willing to take Shredder's place.
Casey:Tiger Claw's still out there. The Foot Clan isn't out of the game yet, dudes.
Mikey:Whatever evil emerges, we'll be ready 'cause we're awesome!
Leo:That's right, Mikey. And we'll do it together. Right, Sensei?