"So, you find the problem with that clutch?" Donatello asks as he enters the barn.

Casey lays on a dolly underneath his car. He huffs, the faint ringing of metal being struck as the dolly wobbles on its wheels. "I found part of the problem," he answers.

He rolls out from underneath the car, holding a squirming, white-feathered chicken. She clucks and struggles against the boy's grip, flapping her wings and beating against Casey's face, forcing him to release her. The chicken hops onto his knee, perches for a moment, then scrambles away.

"Hey, Mikey! Keep your chickens outta the barn, man!" Casey calls, shaking his fist at the retreating bird.

Donatello settles down at his lab table, his eyes downcast as he works on little, meaningless projects. Casey stands up and wanders up to the intelligent terrapin. His eyes soften with guilt and he rubs the back of his neck.

"Listen, Donnie. I'm sorry I went after Speed Demon without you," he apologizes.

"It's fine," Donatello brushes him off. "Me and the guys have been making our own plan to bring that freak down." He adjusts a few bottles on the table, including a small jar of mutagenic gasoline that he had collected after their latest encounter with Speed Demon.

"Donnie, you and I know the hot rod is the best chance we got," Casey insists, getting closer to his frenemy. Donatello swivels in his chair and rests his elbow against the chair back. "We need to team up on this."

The turtle sighs and looks away as he taps his fingers against the wooden tabletop. "I don't know."

"I need your sweet scientific genius, Don," Casey says. He clasps his hands together and flashes a puppy-eyed grin. "Please?"

The purple-masked turtle looks to the teen, pursing his lips. Casey tries to make his eyes even more dewy. The turtle exhales heavily, defeated. "Alright, I have an idea," he says, standing up. "A crazy, awesome idea!" They both look at the car, then at each other. Donatello grins wickedly. "Casey, we're taking a trip down to the basement."

----------

It takes hours and lots of hard work. Casey and Donatello bring in everything they can from the abandoned Kraang scout ship to the barn. They draw up plans. They guzzle energy drinks. They use hammers and blowtorches and every other tool that they possibly can as they work, hardly stopping for breaks.

Eventually, it's completed. Casey and Donatello look at their newly reconstructed hot rod, fit with all kinds of Kraang tech and power ups. What used to be a rusted, red pickup truck is now a black pickup truck with missiles and Kraang-tech tinkered on it.

"This. Is. Amazing!" Casey exclaims, pumping his fists as a childlike glee saturates his gaze.

"Yeah, I know," Donatello says with a nonchalant shrug, "and it's almost ready. I just have to figure out the problem with the artificial intelligence for the onboard computer system."

He sits down in the driver's seat, placing his computer on his lap as he starts tapping out complex codes, his eyes narrowed in concentration.

Unbeknownst to the two boys, a white chicken waddles into the barn, clucking softly. She struts across the floor, hopping onto Donatello's swivel-chair before flapping her tiny wings and reaching the tabletop. She wanders around the new space, knocking over the salvaged bottle of mutagen gasoline. It falls onto its side with a soft ringing noise and the gasoline spills onto the countertop. Enraptured by the glowing substance, the chicken pecks at it, taking some into her beak little by little.

"Here chick, chick, chick," Michelangelo calls as he pokes his head into the barn. He wears a large, floppy sun hat and carries a brown chicken under his arm. "Where are you, little chicky, chick, chick, chick?"

He wanders further into the barn, his gaze drifting to his brother's workspace, and there he finally notices his missing bird. His mouth falls open as he drops his other chicken. The bird clucks and scampers away.

"Oh, snap!" Michelangelo says.

"What?" Casey asks as Donatello stops his work.

Michelangelo points at the chicken and they follow his finger. Their eyes widen in synchronization at the sight. The chicken's brain has expanded, so much so that it sits above her tiny head much like a hat, the sickly green veins traversing it pulsing with every heartbeat.

"Oh, not again! Mikey!" Donatello cries as the chicken hops off the desk and struts around. It's like she doesn't care one bit about her mutated cranium.

"Just what we need, another mutant!" Casey complains, sweeping his hand at the flightless avian.

The chicken ignores their words and heads straight for the car. She climbs up and waddles over to Donatello's computer, where she starts pecking away at the keyboard. The rhythmic beeping of the buttons entices the three boys to come closer.

"Whoa! What's she doing?" Michelangelo asks as he starts to grin widely.

"She's...she's communicating with us!" Donatello gasps. "Those are complex equations!" The chicken looks up at him, tilting her head as the turtle strokes his chin. "Maybe we don't need artificial intelligence, maybe we just need—"

"Dr. Cluckingsworth, M.D!" Michelangelo interrupts, shoving his brother aside and smacking him with the wide brim of his sun hat.

Donatello winces and shoves his brother backwards, just enough so that he's regained his personal space. "Uh, yes, maybe Dr. Cluckingsworth," he says, monotone and almost sarcastic.

"M.D, bro. M.D," Michelangelo corrects.

Donatello kneels next to the chicken. "Um, so, doctor? Can you interface with the hot rod's computer?" he asks.

Dr. Cluckingsworth lets out a brief cluck before turning and pecking away at the controls again. As long lines of code begin to scroll along the computer screen, Donatello and Casey share a fist bump.

----------

Everyone gathers outside the barn the next morning, waiting for the supposedly amazing discovery that Donatello kept gushing about over breakfast. Donatello stands right next to the doors of the darkened barn. Casey is nowhere in sight.

"Alright, Donnie, what are we doing here?" Leonardo asks, crossing his arms over his plastron.

"I give you..." Donatello starts, gesturing to the barn entrance.

The rumbling of a high-powered engine sounds, growing and revving before dissolving into a low hum. Casey drives out into the view of every other teenager present, revealing a new and improved version of Casey's old car. The vehicle pulls to a stop and Donatello grins.

"The Turtle Racer!" he announces.

Awed gasps escape the spectators. Destiny's tail starts to wag. From the back of the Turtle Racer, Dr. Cluckingsworth lets out a happy chirp. Raphael notes the cage and the mutated bird first.

"So...your co-pilot...is a chicken?" he asks slowly, still eyeing the flightless bird.

"She's the onboard navigator!" Casey explains as he hoists himself up, leaning on the front seats.

"You guys really think this...car is gonna stop that maniac?" Leonardo wonders.

"Without a doubt, Leo," Casey replies confidently. "With this baby, Casey Jones can't be beat!"

April shakes her head and exhales as Michelangelo runs his hands over the shiny paint job of the car. Diaval shifts on his feet.

"Well, that's it. You're gonna end up turning into street pizza," April huffs, breaking the silence.

"Street pizza? That's like one of my top ten favourite pizzas!" Michelangelo grins as he hugs the car's hood.

Diaval inches closer to the vehicle. "Looks dangerous," he murmurs, sending an agreeable nod towards April.

"Don't worry, April, with all the Kraang technology we put into the hot rod, it's one of the safest cars on the road," Donatello assures without missing a beat.

"Casey's a pretty good driver too...right?" Destiny asks. The hockey player nods and shoots finger guns her way.

Dr. Cluckingsworth clucks once and promptly lays a glowing blue-green egg, which then rolls along the bottom of the cage before catching on a small metal pipe. Destiny's eyes widen and she grabs Diaval's cloak as he tries to touch the egg through the cage bars.

"What was that?" Raphael asks.

"Oh, that's a highly volatile, radioactive mutagen egg, but don't worry. It's perfectly safe," Donatello says with a proud grin. He hesitates and he rubs the back of his neck. "Sorta."

April and Raphael eye each other uneasily.

----------

The hippie van follows after the Turtle Racer, just able to see the silhouette of Casey's head from their vantage point. The road ahead is almost as dark as the night sky, the headlights from their vehicles the only thing piercing the din. Owls hoot in the distance, mingling with the gentle thrumming of tires against asphalt, all of it alluding to a feeling of serenity. The group knows to stay alert for a certain Speed Demon.

Leonardo drives the van, t-phone in hand. April sits on the passenger side with Destiny sandwiched between them. Michelangelo, Raphael, Diaval, and Donatello sit in the back, peering at the road ahead through the small window between them.

In the Turtle Racer, Casey hears Leonardo's voice crackle through his phone. "We've got the plan down, right?"

"As long as you can keep up in that thing!" Casey retorts.

He speeds up, the engine purring beneath him as he rides. Nothing happens for a few moments as he cruises along. That peace ends all too soon when Dr. Cluckingsworth clucks in alarm and starts pecking out a message on her computer screen.

"What's wrong, doc?" Casey asks, glancing over his shoulder briefly.

A small panel on the front of the racer beeps and a message scrawls out on it that says, "SPEED DEMON APPROACHING." Not a second later, the familiar revving of the Speed Demon's engine can be heard.

"Guys, look out! Here he comes!" Casey warns.

"Roger that, Casey! And remember, stick to the plan!" Donatello says.

A purple sports car appears on the road ahead of Casey, the windows rolled down and headlights shining. Casey can hear the mutant driver inside the car whooping and howling.

"So you wanna play chicken, eh?!" Casey asks. Dr. Cluckingsworth lets out a few appalled noises as she flaps her wings and hops up and down. Casey chuckles. "Sorry, doc."

His eyes narrow and he presses on the gas as Speed Demon keeps coming. The two cars head straight for each other, neither backing out. Ten feet, five feet, two feet...

Casey bows out and swerves around the reckless driver as the very last second, skidding and sliding as he jerks at the wheel. Speed Demon laughs as he soars by, relishing in the victory.

Casey spins the Turtle Racer around and soars down the road after the car. He zooms past the hippie van, making everyone else inside said van turn around and look after him.

"He's doing it again! He's ditching us!" Raphael exclaims.

"Nope, this time it's all part of the plan!" Donatello says with a sly smirk.

Casey picks up enough speed to catch up with the purple car. Inside, the driver notices his competition. His single bulging eye narrows.

"Huh? Bah!" he growls, his voice sounding as though he's gargling gravel. "I'm gonna splatter you across the road. I'll grind you in my grill like the bug you are!"

He cackles madly and rams Casey's car over and over again, the sides bumping and screeching. After a few hits, the teen goes spinning backwards while the Speed Demon races ahead. Casey quickly regains control of his vehicle and continues the chase.

"This'll slow you down, freak!" he calls.

He presses a button, launching a bottle rocket onto the road. It explodes and Speed Demon screams as he drives straight into the heart of the blast. Casey pulls ahead and the demon's sports car careens out of control before skidding to a stop. The mutant cackles and restarts the engine.

Just as the vehicle takes off again, the hippie van rounds the corner and catches up to it. Once they're side by side with their assailant, Donatello opens the side door and leaps out.

He manages to get a grip on the roof of the car, but it jerks like a bucking bronco. Donatello holds on for dear life as the car swerves and twists, but the purple-masked turtle doesn't let go. Instead, he crawls forward until he can reach into the driver's side door and grab the mutant driver by the neck. With a mighty shout, he yanks the driver out and sends the two of them sailing off the car and onto the pavement. The mutant squeals and flails on the asphalt and the purple sports car slides into a tree. Slow-motion laughter plays, winding down before finally shutting off.

Donatello pushes himself up, groaning under his breath as he looks to the smoking wreckage of the sports car. "Casey..." He grins and grabs his phone, speaking into it. "We got him!"

"That'll show you not to mess with Casey Jones!" Casey's triumphant voice returns through the phone.

Donatello stands up, laughing a tiny bit as he turns to the driver. "Not so tough without your car, huh?" he asks as he reaches for his bō.

His eyes widen as he takes in the man. Instead of the wide, bulbous mouth and bulging eyeball, the "mutant" is now a regular guy in a white, wife-beater tank top.

"Where am I? What happened?" the man asks. He notices the tall turtle, letting out a shriek of fear as he scrambles backwards. "What are you?!"

"You're not a mutant?" Donatello asks, stumped. The guy whimpers and faints. The confused turtle tries to put two and two together. "Well, if he's not the mutant, that must mean the—"

Behind him, an engine revs and headlights switch on. He turns around and finds the purple sports car, back on its wheels and full of life. It roars, its hood opening and revealing jaws and a mouth-like entrance. Donatello screams and the car chomps down on him in one swift movement, bouncing and jolting as it consumes the mutant terrapin.

The car transforms, its entire being absorbing Donatello's energy. The hood gains extra armour and the wheels puff up. The roof bursts open and a grotesque version of Donatello bursts through, cackling the entire time. Its lolling tongue is made up of wires and loose piping and its skin is green and covered in bumps.

"More mutant power! That's what I'm talking about!" it screams in glee, gripping onto a bō staff gear shift on its side. "Ya like that? Yeah? Well, it's all me, baby!"

It starts doing doughnuts in place, leaving black marks on the road as its shrieking laughter echoes over the nighttime world. It revs the engine and takes off, heading straight for the road Casey's travelling on. It whips around a corner and comes face to grill with Casey, startling him.

"Donnie?!" he exclaims upon seeing the car.

"Yee hee hee hee hee! Whoo hoo-hoo-hoo! Yeah, baby!" it whoops as it zooms past him, knocking the dark-haired teen's car out of line.

The Turtle Racer jolts to a stop. "You stupid, ugly, pickle-headed..." Casey grumbles, his angry words dissolving into mere mutters. Dr. Cluckingsworth clucks as he tries to start the car again, twisting the key in the ignition desperately. "If I could just start this thing up—"

Leonardo drives up in the van, the window already rolled down. The others peer out the side windows.

"Casey, are you alright?" April asks from her seat.

"Did the plan fail?" Diaval wonders as he pokes his head out the back window. "Could've failed..."

"It's the car! The car is the mutant! It's alive somehow and it's got Donnie!" Casey explains hurriedly as he finally gets the Turtle Racer working again.

Before he can drive away, Leonardo interrupts, "Casey, wait! We need a plan!"

"I've got one! Get Donnie outta that mutant monstrosity, pronto!"

Casey takes off, the Turtle Racer's wheels moving at their top speed. Leonardo frowns, settling back into his seat and starting the engine before following after him.

"Well, at least he's got a lead," Destiny comments with a sigh.

"Let's just hope he can save Donnie," Leonardo responds, his eyes fixated on the road ahead.

Michelangelo hugs his knees to his plastron as he takes a deep breath. "Aw man...I didn't think it was this crazy, dude."

"None of us did," Raphael agrees as he pats his brother's shell.