In a cloudy afternoon, Casey was driving coolly in the party wagon. April was chilling in the passenger seat while Donnie and Donna were sitting together in the back seats. Despite being surrounded by groceries, Donna was completely relaxed while Donnie wasn't relaxing at one bit.

"Ahem! So why am I always stuck in the back with the groceries?" Donnie complained.

Donna rolled her eyes with a groan as she knew that Casey and Donnie are gonna start arguing again.

"Somebody has to make sure the eggs don't break, dude." Casey replied.

"We don't even buy eggs! We have chickens!" Donnie snapped. Then, he suddenly suspected Casey was having ulterior motives on April. "I know what you're up to, Jones! You always get to drive! I wonder why."

"Well, maybe because a giant turtle driving a hippie bus seems a little suspicious!" Casey remarked.

"All right, guys!" April shouted. "I'd just like to have one peaceful trip to the store where the two of you aren't at each other's throats." She looked back to see Donna still relaxing. "At least, someone doesn't seem to complain about the trip."

"Thank you, April." Donna grinned.

Donnie and Casey looked at Donna for a minute before stopped talking to please April for having peace and quiet, but that peace was interrupted when a purple muscle car pulled onto the road and started to edge them off the road. Unfortunately, Casey wasn't gonna let it slide and drove against the purple car off the road. But the purple muscle car pulled a maneuver that sent the car that Casey drove spinning out of control and finally slammed the vehicle into a tree.

"Everyone okay?" April asked.

"I'm good." Donna replied, rising her thumbs up in the air as she was lying on the bags of groceries.

"Nobody forces Casey Jones off the road, huh?" Donnie remarked sarcastically to Casey with a glare.

But Casey didn't snap and slammed angrily on the steering wheel in temper repeatedly.

☆☆☆☆

Meanwhile, the three Turtles and the three Lotus Ninjas sat on the couch as they were watching a Crognard the Barbarian episode inside the farmhouse. But the show got interrupted by the local news on TV.

"Breaking news! A word of warning for those planning on driving tonight Stay home!" The female reporter announced. "Reports are coming in of a mysterious driver running people off the road." The screen displayed a purple muscle car on TV that got everyone perked up. "Stay home! Reports are coming in of a mysterious driver running people off the road."

Donnie, Donna, Casey and April walked into the living room as they watched the news that displayed the same car they've encounter earlier.

"It was him! That's the maniac who nearly trashed us!" Donnie said.

"You ran into that nut?!" Leo and Lee exclaimed worriedly.

"More like he ran into us! Over and over." Casey grumbled as he punched the palm of his hand. "We gotta get back out there and teach that guy a lesson!"

"Casey, it's not worth it." April said, setting down the grocery bags on the table. "Just be glad we're all okay."

"April's right, Casey." Donna agreed, bringing the last grocery bags in the farmhouse.

"Yeah, we're..ugh...mostly okay." Donnie winced. "I got shell-lash trying to save all the food."

Then, April gently massaged Donnie's neck to soothe the pain. Donna could tell that the purple masked ninja turtle immediately was grinning at Casey and watched Casey grumbling as he kicked the couch in anger from the corner of her eye. Donna rolled her eyes in annoyance and walked out of the house.

☆☆☆☆

Outside, Donna was walking down to the forest for some fresh air. She can't stand the tense rivalry between Donnie and Casey all because of their feelings for April. She does feel bad for April because of it, but she's somewhat jealous of the fact that Casey has romantic feelings for her best friend. Donna even remembered soultouching Donnie when they met when saving April's dad Kirby and the two shared a lot of things in common, but she wasn't entirely sure if she wants to move on with him.

Then, her sudden thoughts were interrupted when her eyes caught the sight of the most awesome vehicle she has ever seen. Donna ran over to examine a purple open class superbike lying against the tree, but it was dented and broken. Donna grinned widely as she decided to give this bike an upgrade.

Donna walked back into the barn with the superbike just in time to see Casey continuing to work on the old truck with Donnie's assistance while insulting each other again. But she doesn't have time for that as she was pushing the superbike into the barn and placed it against the wall.

"Hey, Don, may I borrow your tools?" Donna asked as she was interrupting the argument.

"Sure, why?" Donnie said.

"Because I'm upgrading this superbike." Donna replied.

The word "superbike" caught Donnie and Casey's attention. They turned around to see the purple superbike lying against the wall. It was the most awesome vehicle they've ever seen.

"How...when...where...?" Casey stuttered.

"I've found it lying against the tree, so I want to hook it up." Donna explained. "Now, if you excuse me, I'm going to upgrade this baby up."

Few minutes later, Donna have finished upgrading the superbike with a proud smile.

Let's take you out for a test drive! Donna thought.

☆☆☆☆

Outside, four girls were standing on a stretch of highway alongside the cliff side. Donna was sitting on her superbike with a grin. April and Ellie were impressed on the superbike's engine while Ella was deeply amazed of the upgrades.

"You ready, Donna?" Ella asked.

"I'm ready." Donna replied as she placed her feet on the pedals.

"On my mark." April said as she was holding the stopwatch in her hand. "Get set..."

"Go!" Ellie shouted.

At the signal, Donna took off down the road on the superbike. She felt her brown hair soaring freely in the air. She sped past the girls with extreme speed as April clicked the stopwatch.

"Great timing!" April gasped as she was staring at the stopwatch with wide eyes. "Outstanding!"

"Donna's superbike is even faster than my supersonic speed!" Ellie exclaimed.

"She actually pulled it off." Ella admitted. "I'm really impressed."

"But why isn't she stopping?" April asked as she noticed her friend was speeding down the road.

"Come on, let's go get her." Ella answered grimly.

Donna rode her superbike through the road with amazing acceleration, but there was no sign of that purple muscle car anywhere.

In few seconds later, the purple muscle car finally drove next to Donna as if it wants to challenge her. Donna sneered as she was prepared to take that challenge. But her eyes widened wide in shock when she looked closely inside the car from the front window.

"You're a mutant?!" Donna gasped sharply.

"And you were with that kid that tried to stop me earlier!" The purple muscle car spoke. "Wicked bike! But do you ready think that's gonna beat me?"

"I don't know! Let's find out!" Donna smirked.

That's when the purple superbike did something that the purple mystic kunoichi was totally unaware of.

A black sinisterly mist flowed out of the bike engine and swirled itself around Donna from top to bottom, changing herself into a whole new person. Her eyes are now blazing purple. She also wore a dark purple sport bra, dark purple sweatpants with black clovers at the ankles, and black tennis shoes. Donna clashed the superbike against the mutant car with a sly look on her face.

"Listen up, freak show!" Donna spat. Her nerdy voice started to change into a rough, sassy tone. "The name's Moonracer. If you wanna race, then it's a race you get!"

"Bring it on, doll face!" The mutant car cried.

The mutant car and the newly Moonracer Donna raced each other on the road. The mutant car found Moonracer extremely cool and impressive, but it crashed itself into his racing opponent and drove off with insane sinisterly laugh. Moonracer Donna quickly lost control of herself and halted herself before falling off the cliff. Moonracer hissed at the purple muscle mutant car and immediately released herself out of Donna's will, restoring her clothes and mind just when her sisters and her friend had arrived at her direction.

"Donna, you okay?" Ella asked as she dashed towards Donna with April and Ellie.

"Yo, what happened to your bike?" Ellie asked as she was looking at Donna's scrapped superbike.

"Long story, but that car is actually a road mutant!" Donna exclaimed.

"Whoa! A mutant?!" Ellie gasped. "So Casey was right, after all."

"And you went after that thing alone?" April added worryingly.

"At first, but then I felt as if someone or something will taking control of my mind." Donna replied, gazing at her purple superbike. "Like I was a whole different person."

"Well, come on." Ella said, carrying the superbike with her superhuman strength. "Let's get this bike back to the house."

☆☆☆☆

As the girls returned back to the O'Neil farmhouse, Donna carried the superbike into the barn for some repairs. She placed the superbike against the wall and stared it with a firm look on her face as she was furious about losing to the mutant car. Behind her, Donnie and Casey both slowly took their step to comfort Donna.

"Donna, are you okay?" Casey spoke slowly.

"What happened?" Donnie asked.

"That mutant car took me down with it." Donna responded angrily as she turned around to face Casey and Donnie. "Now, get off my back about my business and leave me alone!"

Donna noticed that the shocking yet frightening looks on Donnie and Casey's faces and took a deep breath to calm herself down.

"Look, I'm sorry about my attitude." Donna apologized. "I have no idea why I'm acting this way. But don't worry. Me and the girls are working on our own plans to bring that freak down."

"Listen, Donna." Donnie said. "Casey and I had finished upgrading our sweet side. We want to upgrade your superbike as well. If you're okay with that."

"I'm not sure, Donnie." Donna sighed as she looked back at the superbike.

"Come on, Donna." Casey pleaded. "We need to team up on this. Plus, your awesome scientific genius will improve your superbike all the way to the maximum."

Donna turned around and raised her right eyebrow slowly, watching Donnie and Casey giving her pleading puppy-dog eyes. But the decision has been made.

"Alright, fine. I'm in." Donna said. Then, her voice became serious. "But on one condition. If I ever hear you two argue one more time, then it's over and you boys are on your own with that crazy mutant car."

"We promise." Casey and Donnie promised.

"Now, what do you guys have in mind?" Donna asked.

Donnie and Casey exchanged smirks with sideway glances.

☆☆☆☆

On a stretch of highway under the full moon, the Party Wagon and the Turtle Racer stood on the open road. Leo was on the driver seat and Donnie was sitting on the passenger seat while April, Raph, Ella, Mikey, Ellie, and Donnie were sitting on the back seats inside the van as Casey was sitting on the driver seat of the customized O'Neil family truck.

"All right. We got the plan down, right?" Leo asked.

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

April noticed that Donna wasn't with the others.

"Hey, where's Donna?" April asked.

"Thanks for mentioning that." Donnie smiled as he pointed his finger at the cliff.

Everyone collectively followed Donnie's pointing finger to see Donna jumped high from the cliff on her shiny purple superbike and drove all the way down to halt the bike right next to the Turtle Racer. Donna was wearing a purple jumpsuit with a lavender "D" graphic on the front along with lavender belt, elbow-length gloves, and knee-high boots. She also wore dark purple high-tech visor on her face.

"Whoa." Ellie, Ella, and April said in amazement.

"Nice work on the bike, Donna." Lee grinned.

"Thanks." Donna grinned back. She looked at Casey and Donnie with a smile. "Now, let's get this started."

Casey revved the engine of the Turtle Racer and drove off on the road as Donna followed next to him and Leo drove the Party Wagon behind them.

Then, the chicken mutant that Mikey named Dr. Cluckingsworth began pecking out a message on her computer screen in alert. Casey and Donna stared at the message from a small panel that said "SPEED DEMON APPROACHING".

Seconds later, Casey and Donna heard the sound of the purple muscle car's engine.

"Um, Casey? I think Speed Demon is coming!" Donna exclaimed.

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

"Roger that, Casey. And remember, stick to the plan." Donnie reminded.

Speed Demon revealed itself on the road in front of Casey and Donna, who sped themselves up in rapid speed with narrow eyes. The two cars headed straight for each other while Donna followed them from behind. After a few maneuvers between Casey and Speed Demon, Donnie was able to spring out of the Party Wagon and gripped on the purple muscle car as he reached into the driver's side door and yanked the mutant driver out. That send the car driving straight into a tree. Donna immediately got off her superbike to check on Donnie.

"Casey, we got him!" Donnie grinned to his T-Phone.

"That'll show you not to mess with Casey Jones!" Casey said triumphantly from Donnie's T-Phone.

"Not so tough without your car, huh?" Donna smiled to the driver.

Both Donnie and Donna's eyes widened as they stared at the driver, who has been restored back into a normal human. The human driver looked up at the Donnie with a shriek of fear and fainted quickly to the ground. The purple masked ninja turtle and the purple mystic kunoichi are deeply confused onto what happened.

"I don't get it." Donna said. "I could have sworn he was a mutant."

"But, if he's not the mutant, that must mean the..." Donnie said.

"Oh, no." Donna said in realization.

Donna spun around to see bright light flashing from behind. Donnie noticed the purple mystic kunoichi's frightening look and slowly turned around just when the car's hood open wide that revealed jaws and a mouth-like entrance. Donnie screamed as the car began chomping him down in one swift movement. The whole car began to absorb Donnie's mutant energy and transformed itself into a grotesque version of the purple masked turtle bursting through the car roof.

"More mutant power! That's what I'm talking about!" Speed Demon cackled in glee. He looked down at Donna with a smirk. "Ya like it? Yeah? Well, it's all me, baby!"

Donna gasped in horror and backed away from the newly transformed mutant car. But she turned around to see the purple superbike block her path. The superbike's lights flashed in dark green and began fusing itself into Donna's fleshy skin, causing her to scream in pain and horror. The whole bike began to absorb Donna's mystic energy and transformed itself into a polished automaton version of the purple mystic kunoichi extending out a pair of black inline skate-like wheels.

"You're not the only one with an upgrade, baby." Moonracer grinned. "Let's have fun tonight."

Speed Demon gripped onto Donnie's Bo staff as a gear shift on his side and Moonracer revved her wheels as they took off to head straight on the open road. They zoomed around the corner of the road that startled Casey, who couldn't believe what he's seeing with his own eyes.

"Donnie?! Donna?!" Casey exclaimed.

"Yee hee hee hee hee! Whoo-hoo-hoo-hoo! Yeah, baby!" Speed Demon whooped.

"See ya later, loser!" Moonracer shouted.

Speed Demon and Moonracer zoomed past Casey that knocked the Turtle Racer out of line. Casey grumbled for the result of his friends and tried starting up the Turtle Racer again, but Leo drove the Party Wagon up next to him and rolled down the window.

"What happened?" Leo asked.

"It's the car and the bike! They're mutants!" Casey explained hurriedly as he finally started the Turtle Racer. "They're alive somehow and they got Donnie and Donna!"

"Casey, wait for a second! We need a plan first!" Lee said.

"I've got one! Get Donnie and Donna outta those mutant monstrosity, pronto!" Casey said.

Casey drove off to chase Speed Demon and Moonracer, leaving Leo follow after him inside the Party Wagon.

Then, Casey caught up right behind Speed Demon and Moonracer as he rammed into them with the Turtle Racer.

"You again?!" Speed Demon roared.

"He doesn't give up, doesn't he?" Moonracer hissed.

"Let my friends go, freaks!" Casey demanded. "Or I'll take us both down!"

"Never gonna happen, Casey Jones!" Speed Demon shouted. "Donatello belongs to Speed Demon now, baby!"

"And Donatella is my new power engine, sweetheart!" Moonracer snapped. She then formed a sinister smile on her face. "Hey, how about we race for it? You win, you get your friends back."

"But if we win, we get your super hot rod and all that sa-weet technology!" Speed Demon added.

"Fair enough." Casey said with a scowl.

"And I get you, Casey Jones! The only driver worthy of my competition." Speed Demon said sinisterly.

"It's a deal!" Casey shouted.

"First one to dead man's curve wins!" Moonracer said. "Starting...now!"

Speed Demon and Moonracer sped off in fast speed as Casey was speeding behind them. The Party Wagon caught up for everyone to see the race up front.

"Dudes, we need some faster wheels!" Mikey shouted.

"For real!" Ellie agreed.

"What are they doing?" Leo asked

"Looks like a race to me." Raph replied.

"Seriously?" Ella gasped.

"Are those hideous things...Donnie and Donna?" April exclaimed.

"I've seen a lot of gross things, but this is disturbing." Lee said with a deadpan face.

Casey, Speed Demon, and Moonracer kept racing to the very end, but Casey was able to use clever tricks that Donnie installed to confuse the mutant vehicles.

Unfortunately, that didn't stop Speed Demon and Moonracer from claiming their victory.

"See ya at the finish line, Casey Jones!" Speed Demon and Moonracer cackled.

"I don't care about winning the race! I just want my friends back!" Casey retorted.

The Turtle Racer accelerated even faster to catch up with the mutants as Casey set the car on autopilot, leaving Dr. Cluckingsworth in charge of the speeding vehicle. Casey jumped out of the Turtle Racer and landed onto Speed Demon, pulling the possessed mutant turtle free from the vehicle. Moonracer noticed Casey and turned back around to attack him, but Casey jumped onto Moonracer's neck and electrocuted the possessed mystic kunoichi from the bike. The purple muscle car and the purple superbike crashed into the cliff side. Casey got up from the ground as he ran over to Donnie and Donna, who went back to normal.

"Donnie! Donna! You guys all right?" Casey asked.

"Yeah, I think so." Donnie replied with a slow nod.

"I'm good." Donna said with a groan.

Casey, Donnie, and Donna noticed that Speed Demon and Moonracer are speeding up towards them. The two mutant vehicles drove forward straight at Casey, but Donnie took out his Bo staff and jumped up to lodge his staff in Speed Demon's open jaws while Donna transformed her arms into large spearheads and fired a large number of metal spears towards Moonracer multiple times in rapid succession.

But unfortunately, Speed Demon snapped Donnie's Bo staff in two and Moonracer shook numerous metal spears off. Speed Demon and Moonracer sped forward towards Donnie, Donna, and Casey at full speed until the Party Wagon suddenly appeared out of nowhere and smashed itself into the mutant vehicles that sent both Sped Demon and Moonracer flying off the cliff.

"We'll be back!" Speed Demon and Moonracer screamed.

With that, Speed Demon and Moonracer ended up exploding in a flash of green light.

"Whoo-hoo! The Party Wagon takes the win!" Mikey and Ellie cheered from the van.

"Yes!" Donnie, Donna, and Casey whooped with high fives.

Donnie, Donna, and Casey watched Dr. Cluckingsworth return inside the Turtle Racer.

"You did good, too." Donnie said.

"I'm so glad you three are okay!" April said happily as she hopped out of the van. Her eyes stared directly at Donnie and Casey. "And I'm so glad you're actually getting along!"

"Thanks, red." Casey smiled. "Hey, Donnie, how awesome was me grabbing your giant head, huh? So weird!"

"Yeah, or when you used the mutagen boost? It actually worked!" Donnie responded excitedly.

Donna watched as Donnie and Casey started to praise each other obnoxiously on the fight with Speed Demon and Moonracer. She rolled her eyes with a smile and moved herself right next to April as she noticed that her best friend's joy has been short-lived.

"Guess they're becoming best friends in a whole weird level." Donna smirked.

"Hmph...I thought I was glad they're getting along." April said dejectedly.

"I know how you feel, April." Raph said as he moved next to April.

"You and me both." Ella agreed as she moved next to Donna.

April wrapped her arm around Raph's shoulder and leaned against him as Donna rested her arm on Ella's shoulder and leaned against her. They watched as the whole new bromance between Donnie and Casey has been born between the nerd and the rebel.