[Episode starts with an angry Falco trying to recreate the project.]

Falco: They all thought they could stop me. The corporate fools who pulled my funding. The scientific community who shunned me. Those turtle freaks who thought they got the last of my mutagen. But they were wrong. Even with this tiny amount and nothing but these disgusting sewer rats to experiment on, I have nearly recreated my psychic neurochemical. And when I do, the shortsighted idiots who rejected me will tremble before the power and genius of Dr. Victor Falco.

[The rats bit out the wire, setting off an explosion.]

Falco: No, no! Help me! Please! Help! Help!

[The rats started to come to him. The man smiles evilly and cackles. He is now born as the Rat King]

[Theme song.]

(Master Splinter was standing in the dojo, with his back to the brothers. A few feet away the brothers took a knee and discussed the plan.)

Leo: Okay, here's the plan. Donnie, you're both gonna strike first with Y/N following behind. 

Y/N: (Nods) Got it.

Donnie: No, wait. You want me to come at Splinter? Y/N may hold his own, but I'll get pummeled.

Raph: Well, getting pummeled is your specialty.

Y/N: Not the time Raph.

Leo: Trust me. It's all part of my plan to catch Splinter off-guard.

Mikey: Uh, Leo, don't take this the wrong way. But against Splinter, your plans always get our butts whipped.

Leo: Okay, new thought. Mikey, you attack with Y/N following behind.

Y/N: (Smirks at Mikey) Should'a kept your mouth shut.

Mikey:(Turns to Donnie) He took it the wrong way.

Raph: Enough talk. Let's do this.

(Leo nods and they all turn to there rat master. The boys start to walk over to Splinter. Leo and Raph to the right, Donnie and Mikey to the left, and Y/N right in the center. Even with his eyes closed, Splinter still knew they were coming. Because of his great hearing. He turned and prepared for battle. Mikey ran at his father and jumped into a drop kick. Time seemed to slow down. Splinter opened his eyes, as he felt air rushing towards him after hearing rapid, soft foot steps coming from the behind. Splinter grabbed Mikey's leg and threw him onto the floor. Mikey yelped as he was kicked away. Y/N soon came up and attempted a kick, but his foot was grabbed and he was about to be kicked if he didn't break out in time. He soon faced splinter in hand to hand combat.)

(Soon, it ended with Splinter grabbed by his tail which made him yelp and vulnerable long enough for Splinter to kick him and crash into the wall. All the while, Raph was sailing mid-air, ready with a punch, Donnie and Leo were running to Splinter. Splinter moved out the way, just in time to avoid Raph's fist hitting him in the head. Then dodged his charging attack at the same time as Donnie's Mid-air kick. Then dodged Leo's side kick.)

(Splinter grabbed Donnie's leg and Raph's arms. He swiftly let go of Raph arm and spun to knock Donnie off his other leg. As Donnie circled in mid-air from the move, Splinter kicked him into Raph. They both went flying. He turned to hit Leo in the face, but the eldest turtles ducked under it. Seeing an opening, Leo quickly let a punch fly and hit Master Splinter right in the cheek. Only then did Leo understand what he did and instantly felt afraid and guilty. Leo pulled back his hand, and Splinter seemed frozen.)

Leo: Uh! Sensei, I'm sorry.

(Sensei turned with what seemed like an angry look on his face. Leo tried to explain, but was flipped over. Splinter held up his fist. Donnie, Raph and Mikey stared at the scene.)

Donnie: Oh man. Leo's a goner.

Mikey: Oh, nodie dodie.

Y/N: Master, breath.

(Splinter relaxed.)

MS: Thank you Y/N. Well done, Leonardo. But just when you had the advantage, you hesitated, and that made you vulnerable.

Leo: Hai, Sensei.

MS: Now, that is all for today. Unless you care for a rematch.

Donnie: No thanks.

Mikey: I'm good.

Y/N: Yeah, I think we're all set here.

Mikey: Leo!

Raph: Not bad.

Donnie: Dude, I can believe you actually tagged Sensei. 

Y/N: That was epic.

Mikey: (Takes Leo's hand) That hand that punched Splinter. You know you can never wash this again.

Leo: I gotta say guys, it was all teamwork. We are definitely getting better.

Donnie: You think we might be catching up to Splinter?

Mikey: Yeah, maybe soon, we won't need him to train us at all.

(But, unknown to the turtles, Master Splinter heard their entire conversation. The turtles walked out of the dojo laughing while Y/N stayed behind frowning, but soon he exited the dojo as well.)

Y/N: (Catching up to his brothers) Hey, I'm glad that we are improving. But I don't think we should be counting down the days when we don't need Sensei anymore. We you should cherish the time we have now.

Mikey: Why?

Y/N: Just because Leo landed a hit doesn't mean that we're catching up to Splinter. And besides it's just hurtful to say that you're excited that you don't need someone anymore.

Leo: ..Wow.

Raph: You always know how to make us feel bad.

Y/N: But I also help you with your problem. This is one of my specialties.

(Time-Skip)

[Meanwhile at the rat king's lair]

Rat King Falco: Through your eyes, brothers, I finally see the world for what it really is. This city is infested. 8 million parasites, scrambling around in their pointless lives, spreading disease, forcing us to live in the shadows, like vermin. No more. They are the true plague. Together, we shall rid this city of humanity and reclaim it for ourselves. And no one, not even those vile turtles, shall stand in our way.

Police: Oh, that's disgusting.

Carlos: Citizens are fleeing the city in droves, but authorities say that while the rash of rodent activity is unusual, it's no cause to get rat-tled. For channel six news, I'm Carlos Chiang o- [Rats attack him] Holy moley! Get them off me! Get them off-

[April was walking down the street and sees a small rat.]

April: Aw, hey, little fella. Where's your mama? [She saw the rat horde.] Sorry I asked.

Rat King: You've done well, brothers, but our fight is not yet won. Those turtles are still out there, and I fear that even you may not be able to stop them. But I sense a kindred spirit who can. A fellow rat, who once knew the bonds of humanity as I did. A great warrior, who shall serve as both my eyes and protector. Join me, join me!

(In the Lair)

(In the lair, Master Splinter was training, trying to forget what his sons had said. But he just couldn't seem to shake it. Soon, would they not need him anymore? Then he heard a voice in his head, clear as day. "Join me. Join me." it said. Master Splinter's eyes went red for a second. But he snapped out of his small trance and yelled. He fell to the ground, on his knees. Even though everyone was in different rooms they could still hear the scream. Donnie, who was working on his patrol buggy turned off his blow torch. He ran out the room to see the rest running to the dojo, Vixen being the fastest. When Donnie came in, The 4 were crowded around their Master.)

Donnie: Sensei, are you okay?

MS: I am fine.

Vixen: Not to be rude, but no one just screams out if they were alright.

Leo: Are you sure you're alright? You don't seem-

(Leo was interrupted by bird songs and harp music.)

Donnie: Hey, that's April's ringtone!

(Mikey and Raph started to make kissy noises. Y/N stood up and slapped them both on the back of their heads.)

Y/N: Quit it.

Donnie: Hey April! I mean- hey April~. I mean-

April: Donnie, stop talking. I need some help. I'm having a little bit of a pest problem.

(April looked down to see the millions of rats she got away from. By climbing a telephone pole.)

Donnie: Don't worry April. We're coming.

(Even thought it was daytime the brothers still went topside. As they hopped from rooftop to rooftop the people below ran away from the many, many, many rats.)

Mikey: Oh, wow. The city is so beautiful in the daytime. Except for the, you know, billions of rats.

Donnie: Actually, the entire rat population of New York is only about 36 million, which-

Raph: I will smack you out of your shell.

Y/N: Uh, guys, we may have a problem.

(The 5 stopped to see to many rats swarming around the telephone pole that April was gripping on for dear life.)

Mikey: Oh rats. Ha. Get it?

Raph: For the 14'th time, yes!

Y/N: I'm so proud of you, Raph. It's been 10 minutes, and you haven't smacked anyone. Which crushed you're old record of 2.

Donnie: We're coming, April. Don't go anywhere!

April: Where could I possibly go?

(Raph, Leo, and Y/N swung some grappling hooks and threw them at the wooden pole. Raph swung and landed on the pole, knocking off rats that were climbing up. Leo and Y/N did the same. The others quickly followed suit.)

(Raph and Y/N noticed that the rats were still climbing up the pole.)

Raph: These stupid rats are starting to get on my nerves.

Donnie: Rat's aren't stupid. Despite their small brain size, they're remarkably (A rat fell on Donnie's face.) ow!

Raph: I warned ya.

Leo: Raph, put down the rat and keep-(Hears slurping and looks at Y/N who has a rat tail waving around from outside his mouth.) Y/N!

Y/N: (Spits out Rat) Sorry, I still have some cheetah urges.

April: Hurry!

(The brothers kept climbing, but unknown to them, the rats were chewing on the base. The telephone pole started to tilt to the side and April was starting to lose her grip. The only thing keeping the pole up was the telephone lines. Then April let go. Donnie gasped and pushed off. He swung and caught April. Then landed on the pole again.)

Y/N:  Donnie, great catch!

Donnie: As long as Donnie's here, you have nothing to-Oh boy.

(The rats have finished chewing the wood and know they were all falling. The pole suddenly stopped because of the wires. The 6 were just hanging there.)

April: Oh, okay. I appreciate you guys coming to help, but how is this better than getting eaten by rats?

Mikey: At least it'll be quick. With rats, they chew and chew and chew and chew and chew-

Y/N: Okay, we get it. (Jumps onto the beam and begins to walks across it) Come on we got to move!

(The others started walking across the beam. The second to last wire snapped. They all turned and gasped.)

Y/N: Stop being stupid horror movie people, AND RUN!

Leo: Hurry!

(They all ran across the beam and it snapped. They were still on it, so the beam fell. Because there was so much weight on the other side they were launched onto the next roof. They all fell into a pile and the screeching of rats followed. They looked over the edge.)

Leo: Chew on that, rat finks!

(He looked behind his to see everyone staring at him.)

Leo: Oh come on. That sounded cool.

Y/N: (Shrugs) Meh.

April: Does anyone know what the heck is going on?

Donnie: I'm not sure. But whatever it is, this attack is extremely well coordinated. Obviously, there is a higher intelligence at work here.

Raph: Well, that rules out Mikey. (Y/N smacks him in the back of the head) Ow!

Y/N: Not the time bro.

Donnie: I'm serious. Someone or something is controlling every rat in the city.

Raph: Wait a sec. Every rat?

Leo: That means that Splinter could be-

Y/N: Oh rats.

(Master Splinter was in the lair, sleeping. But the voice would not leave him in peace.)

Rat King: Why fight it? You know in your heart you belong with the Rat King.

Splinter: Leave me. I am not one of your rats to control.

Rat King: You're right. You are so much more. We are so much more. And together, we will be unstoppable.

Splinter: No. You and I are nothing alike.

Rat King: We've both lost all we held dear. We've both become outcasts from society. And we've both come to see the world through the eyes of rats.

Splinter: No. I am a man. I am Hamato Yoshi.

Rat King: Not anymore.

(Outside of his sleep the brothers and April were watching him sleep and looked him with skeptical faces.)

April: Is he okay?

Raph: Donnie, you're the smart one. What do we do?

Donnie: M-maybe we should poke him?

Leo: Good idea. Mikey poke him.

Mikey: No way, I'm not poking him. You poke him

Leo: Okay, we'll put it to a vote.

Leo/Donnie/Raph: Mikey.

Mikey: I want a recount.

Y/N: And all in favor of Mikey not poking him say "I"

April/Mikey/Y/N: I

Y/N: Looks like it's a tie.

Raph: Would someone just poke him?

(Everyone looked to the sleeping rat. Soon MIkey was holding Donnie's staff, with Y/N because he wants his brother to be safe. With Mikey holding the staff it was shaking a little.)

Donnie: Easy, easy.

Vixen: I know what to do!

Donnie: Careful not to squeeze the-

(A blade popped out the end on the staff, because Mikey accidentally squeezed the hidden button. The boys screamed. The sudden screaming made Y/N let go of the staff and Mikey started fumbling with it and threw it to the ground. Donnie picked it up and gave it to Y/N, not letting Mikey touch it.)

Donnie: Okay, let's try it from the other end.

Y/N: (Nervous chuckling)

(Y/N started poking Sensei, but getting no reaction.)

Y/N: He is in a deep sleep.

Mikey: He is totally out of it.

(Y/N constantly poked him in the nose.)

Mikey: Dudes, check out the nose nuggets.

Vixen: (Annoyed Sigh)

(In Splinter's Mind)

Rat King: We have evolved beyond humanity. We have no need for them, but we can help each other. Join me, and you shall hide below the surface no more.

Splinter: No.

(Back in the real world)

(Mikey had taken the staff from Y/N and started moving Splinter's lips and imitating him.)

Mikey: Michelangelo is awesome. He is the smartest, handsomest, Butt-kicking-est of all my....woah! (At that moment Master Splinter woke and threw Mikey onto the other side of the room.)....sons.

Y?N: Sensei, are you okay?

MS: Not Y/N, I am not. It would appear that your former adversary, Mr. Falco has returned.

Y/N: Falco? Again? I hate that guy!

Donnie: Falco's behind this. How is that possible.

Y/N: Anything's possible when your crazy, smart and stupid all at the same time. He must have still wanted to become a psychic and experimented on himself.

MS: Yes, he had acquired a telepathic connection with every rat in New York. And he now calls himself the rat king.

Mikey: Oh great. So now we're letting the bad guys name themselves? We gotta take him down.

MS: Yes, Michelangelo, you do. The rat king will not rest until he has total control of this city...and my mind.

Leo: Sensei?

MS: Everything I knew is gone. My wife, daughter, my clan, even my humanity. You 5 are all I have left.

Raph: Don't you worry Sensei. We'll stop him.

Y/N3: But we gotta find him first.

MS: When the rat king attempted to take control of me, I could see into his mind. You will find his lair in an abandoned utility junction beneath herald square.

Raph: Let's go play exterminator.

(Master Splinter cried out in pain as the rat king tried to convince him again. April, Y/N, and Leo were by his side.)

Leo: Fight him Sensei.

MS: I will. Just hurry.

April: It's okay guys. You go after the rat king. I'll stay with Sensei.

(Y/N looks down and sees the photo that Splinter dropped. There was him, when he was human, his wife and their child.)

Y/N: Come on guys.

(The brothers soon ran out of the dojo to stop the rat king.)

(The brothers were walking in the sewers, as Mikey talked nonstop. which the boys found it annoying.)

Mikey: What's gonna happen to Splinter if we can't stop the rat king? Which by the way, lamest villain name ever.

Donnie: Let it go already.

Raph: We're gonna stop the rat king, and Splinter's gonna be fine. Right, Leo?

(There was squeaking, The 5 looked down to see a rat running between Leo's feet.)

Donnie: Shh, quite. Do you guys hear that?

Y/N: Oh, you mean that rumbling sound that will obviously be the epitome of horror for the day?

(The 5 looked down the tunnel to see a sea of rats coming their way.)

Raph: You gotta be kidding me.

Mikey: Aw ra-

(Raph covered Mikey's mouth before he could finish his sentence.)

Donnie: Uh, Leo? Any ideas?

Leo: Just one. Run!

(The 5 started running down the tunnels.)

Y/N: This is so disturbing.

(Everyone jumped off the wall and grabbed onto the pipes above. Everyone except Mikey, who was still running.)

Y/N: Mikey, what are you doing? Jump!

(Mikey jumped onto the pipes but had to kick off a couple of rodents that caught his leg. He wrapped his legs around the pipes as well in a state of panic. A rat crawled onto his head and bit him. The rat then jumped off him and into the river of rats.)

Mikey: Oh no. They've got the taste for turtles now.

Leo: Come on. Just keep moving.

(Leo, Donnie, Raph, and Vixen continued on, hanging by the pipes while Mikey was crawling upside down.)

(A/N: I'm going to skip the fight between April and Splinter and just go straight back to the brothers.)

Mikey: I'm just saying, I can think of a million better names than the rat king.

Y/N: Like what? 

Mikey: There's ratzilla, the verminator, lord rattington-

Leo: Can it Mikey. We're almost there. The utility chamber should be on the other side of that wall.

Raph: Uh, you mean that disgusting, furry, squirming wall?

(The 4 other brothers looked up and saw that the tunnel was being completely blocked by rats.)

Y/N: Well this sucks.

Donnie: How are we supposed to get past that?

(Leo looked down and saw that there were metal containers.)

Leo: Raph, those barrels. Ventilate 'em.

Raph: You got it.

(Raph through two ninja stars at the barrels, and now they were leaking chemicals.)

Donnie: Uh, Leo, you do realize those chemicals are highly combustible.

Leo: You don't say.

(Leo used his katana and cut a electric wire and it started swinging towards the chemicals, sparking. As soon as the spark his the liquid, the whole thing exploded. Rats flew everywhere and there was now a way in.)

Leo: Let's move.

(The ninjas entered a large broken down room, with floors that were completely cracked open, large pipes showing from the walls, and chipped floor. They stopped when they saw a man wearing cape and large hat standing on the floor above them. He had bandages around his eyes, his teeth were messed up and his skin was so...ew.)

Rat king: Ah, my mutant friends, we meet again.

Raph: Except last time, Falco, you weren't wearing a sad Halloween costume.

Y/N: Burn...

Brothers: (Laugh) 

Rat king: I am the rat king!

Mikey: (Cough Cough) Lame.

Leo: Sorry, we don't have any treats for you. But we do have some tricks.

(Suddenly, Donnie's ringtone for April played.)

Raph: Way to ruin the moment, Donnie.

Donnie:(Picks up his phone) Uh, April, now's not really the best time.

April: Donnie, it's Splinter. He's gone.

Donnie: What do you mean gone? Gone where?

MS: Here.

(Master splinter walked into the room, eyes red. The 5 brothers gasped.)

Y/N: Oh, boy.

Leo: What's wrong with him?

Donnie: It's like his brain is completely turned off.

Raph/Mikey: You mean like Mikey?

Mikey: Dude, you are so predictable.

Y/N: Sensei, snap out of it.

MS: You waste your words. This is where I belong, with my brothers.

Rat king: He is mine now. Imagine the delight when I realized that controlling your master would not only make me invincible. But also be the key to your demise.

Y/N: I don't know. You jumped up and down and squealed, like a school girl getting her Sem-pi to notice her? (Chuckles)

Rat king: Splinter, destroy them

(Master Splinter started walking towards the 5.)

Leo: Sensei, DONT!.

(Master Splinter stopped walking, as if he was gaining control again. The rat king took of hat and bandages and used his mind control which was now, much stronger. Master Splinter's eyes glowed red again and he started walking towards the brothers.)

Donnie: Are we really going to do this?

Raph: Remember, we did beat him once. Kind of.

Leo: Yeah, and we can beat him again. We can do this, guys. Do not hesitate.

(The brothers and Splinter was  just staring at each other. The rats crawled off Splinter, knowing the fight was about to start. Master Splinter took his sword from the sheath and it made a sharp metal sound. Leo took out his katana, while the other ninjas had their weapons out.)

Leo: Take sensei down.

(The brothers started to attack their rat master, but weren't doing so good. They all jumped up to strike Splinter with their weapons, but when they landed, they saw he was gone. Behind the brothers, Master Splinter came into view. The ninjas looked behind them, knowing what was to come. Mikey was thrown onto the wall on the floor above. Raph was thrown on the other side of the room. Y/N was thrown against a large pipe. Leo was thrown on the floor above, hitting his shell on a pipe. He looked up to the sound of Donnie being launched, and saw his little brother coming towards him, head first. Leo slid out the way and Donnie hit his head on the pipe, pushing it into his shell. He popped his head back out.)

Donnie: I just had a horrible realization. He's been going easy on us all these years.

(The rat king laughed, as Y/N got back up and charged at Splinter. He tried to alash at him, but he quickly dodged and was grabbed by the tail. Splinter soon flunged him over his shoulder and right into a wall.)

Y/N: (Hits wall) Gah!

Leo: Y/N!

(Then, Leo duels with him. Splinter quickly knocks the katanas out of his eldest son's hands and prepares to kill him.)

Leo: Sensei, please. Wait!

Rat King: Finish him.

Leo: Remember who you are. (Leo takes out the picture of him and his human family.) 

(Splinter narrowed his eyes, as if he was trying to remember.)

Leo: Donnie, Raph, Y/N now!

(The three brothers pin Splinter down as still struggles.)

Leo: Please, father. We need you.

Rat king: Don't listen to him, brother. Your place is with me.

Y/N: How did you get down here?

(Master Splinter threw all the boys off him. Leo was once again pinned under him. He raised his sword up, ready for the final strike. All was quiet until Splinter's eyes didn't glow red anymore.)

MS: My place...is with my sons!

(Master Splinter ran over to the Rat king who had just got up and hit him with his two fingers, blasting him back. The rat king crashed into the wall and feel to the ground, knocked out. The brothers ran over to get a better look at what their father had done. When that was over, the ran over and gave him a hug. They watched as a wave of rats washed over Rat kings body and took his away.)

Mikey: And that's the last we'll see of count ratula.

Y/N: (Dead-panned) Seriously?

Everyone: ?

Mikey: Yeah, all right. It's rat king. But I'm naming the next one.

(Master Splinter was in the dojo meditating with Y/N. He heard someone walk in.)

Leo: Sensei, are you sure you're okay?

MS: I am fine thanks to you. You did well, my son. (Looks at Y/N)

Y/N: Both of you.

Leo: Well, you did hesitate, and hesitation leads to vulnerability.

Mikey: We did pretty good too, huh?

MS: Yes, I am proud of you all.

Leo: Who knows? Maybe one day, we'll be even better martial artists than you.M

S: Remember my son. Everything you know, I have shown you.(Then Splinter flipped Leo into the wall.)

MS; But, I have not shown you everything I know.

Leo: It's great to have you back, Sensei.

Y/N: Ditto. (Smiles)

(Hope you enjoyed the chapter!!)