On a rooftop in NYC one night, the turtles, their allies, and the Rainbooms were practicing some moves, while Carmen, Zack, and Ivy were following along.
“Good job, ninjas. Keep it up.” Leo instructed, as they did some spin kicks.
“Remind me again why we're doing this on the surface?” Raph asked Leo.
“Because it's a beautiful night.” Rarity noted, as she threw some air punches.
“And you all could use some air.” Applejack added, as she did a sweep kick.
As Sunset and Carmen were sparing, the Rainboom spoke, “Good job, Carmen. You learn fast.”
“When you've trained in combat with a crime syndicate you learn plenty.” Carmen replied.
Rainbow and Twilight were helping Zack and Ivy keep their stances, “Ok, guys. Like this.” Rainbow did a few air punches before giving an upward kick.
“Alright, my turn.” Zack said, as he mimicked Rainbow's moves, but upon doing the upward kick he leaned back a little too far and landed on his back.
“Ooh.” Twilight cringed.
“Maybe next time don't lean back so much.” Rainbow suggested, as she and Ivy helped him up.
“Noted.” Zack groaned, as he straightened his back out.
“Hey, thanks again for letting us join ya in this exercise.” Ivy told the group.
“No prob, Ive.” Mikey replied.
“Don't know why Shadowsan ain't here to join us.” Zack said.
“Shadowsan is doing his own reconnaissance in the city.” Carmen reminded the boy.
“Speaking of reconnaissance,” Mikey began, “We should do a recon on pizza.”
“I agree with Mikey.” Zack said.
“Same.” Keno admitted.
The others looked ready to break until April stopped and concentrated. Everyone watched her, before she motioned to a nearby water tower behind them. Leo gave everyone the hint to play dumb and keep moving. Watching from the water tower was a figure who looked ready to move, only to see two shadows falling over. It looked and saw Raph and Karai.
“Bit late to be bird watching, isn't it?” Raph asked rhetorically.
The others waited, until Raph and Karai came down with their stalker, “We found this one spying on us.” Karai told them.
“Please, I'm not a spy!” the figure pleaded with a familiar female voice.
Carmen looked at the figure seeing it was a woman with short cut navy blue hair with a blue shine and fair skin. She was wearing darkly rimmed round glasses, and a black suit.
“Jules?” she asked.
“Huh?” the others asked.
“Raph, Karai, let her go!” Carmen ordered.
“What?” the two asked.
“She's an ally.” Carmen assured.
Raph and Karai let the woman go who straightened herself out, “Thank you.”
“Jules, fancy meeting you in the Big Apple,” Carmen began, “Looking to see the Museum of Natural History, and not on business for once?”
Jules sighed, “Oh, I'd wish. But it's always business, Ms. Sandiego.”
Mikey blinked and whispered to the others, “Dudes, I think they're flirting with each other.” they rolled their eyes.
The newcomer turned to everyone, “Greetings, I am Julia Argent. I'm terribly sorry my observation led you to think I was an enemy. But I assure you, I am on your side.”
“Well, Ms. Argent...” Leo began.
“Please, call me Julia.”
“Julia. You don't seem too surprised by our appearance.” Leo motioned to himself and his brothers.
“Oh, that's because I was briefed about you before coming here.”
“Briefed about us?” Donnie asked.
“Yes. I know about you and everyone else here,” Julia began listing off, “You're Leonardo, Donatello, Raphael, and Michelangelo.”
“Whoa, she knows us.” Mikey gasped.
“And I admit, you have very astounding names for mutant turtles.” Julia added.
“Well, thank you.” Donnie replied.
“And I know of your friends here in New York,” she turned to their human allies, “April O'Neil, Casey Jones, Karai Hamato, Shinigami, Keno, and Fugitoid.”
“Dudes, she knows too much.” Casey said suspiciously.
“Let's hear her out, Casey.” April replied.
Julia turned to the Rainbooms, “And I'm finally meeting with the famous Rainbooms.”
“You know about us too?” Rainbow asked.
“Indeed, Rainbow Dash. Twilight Sparkle, Sunset Shimmer, Rarity, Applejack, Fluttershy, and Pinkie Pie.”
Pinkie popped in beside her, “Well, it's nice to meet you, Jules. Here, a cupcake for a new friend.” she presented her with a cupcake.
“Thank you,” she accepted it, “I have to admit, I did not really expect to learn about magic and the idea of an alternate world populated by ponies. But if your details are anything to go by, I believe them.”
“How'd you get details on us?” Sunset asked.
“All will be explained, Ms. Shimmer. My superior wishes to meet you all.” she pulled out a click pen from her pocket and clicked it before putting it on the ground.
“What's she doing?” Keno wondered, as the pen projected a hologram of another woman before them.
“Whoa.” Donnie gasped.
“Remarkable.” Fugitoid admitted.
This woman looked much older, had dark skin, with buzz-cut blond hair and wore a gray suit uniform over a navy blue blouse. She also wore a pearl necklace, small earrings, and a pen in her jacket pocket.
“Ms. Argent.” the woman greeted.
“Chief. I have made contact.” Julia explained.
Chief looked and saw Carmen, “Carmen Sandiego.”
“Chief.” Carmen greeted back.
Chief looked to see the New York ninjas and the Rainbooms, before smiling, “Ninja Turtles and Rainbooms, I presume?”
“Uh, who're you?” Applejack asked.
“You may call me Chief.”
“Chief of what?” Casey asked.
“I am head of ACME, and what we want is what Carmen here is after.”
“What she's after?” Shini wondered.
“The exposing of VILE.”
The group was curious, as Leo asked, “You're called ACME?”
"Just what is ACME?" April wondered.
“The Agency to Classify and Monitor Evildoers.” Chief explained.
Carmen spoke, “Chief, how do you even know about these guys?”
“While VILE is our number one priority, we monitor all parts of the world for any evil-activity. And New York has been busting with activity relative to that.”
“Then you know about mutants, the Kraang, the Triceratons?” Leo asked.
“Even the Shredder, Leonardo.” Chief replied.
“And you know about what we've been dealing with?” Sunset asked.
“Indeed so. ACME's kept tabs on all your exploits involving 'Equestrian Magic'. Of course it helps when one of our youngest field agents is keeping tabs on everything where you girls are from.”
In a cafe close to CHS, Lyra and Bonbon were enjoying a milkshake together, until Bonbon let out a sudden sneeze.
“Achoo!”
“Gesundheit.” Lyra replied.
“Thank you. That was very unexpected.” Bonbon admitted, before shaking it off, and the two continued to enjoy their milkshake.
Back with the ninjas, Chief continued, “When I first learned about both groups, I couldn't believe it either. Mutant Turtles trained in ninjitsu, or even seven teenage girls wielding magic not of this world.”
She was cut off as Mikey was moving his hand all through the hologram of Chief's waist, “Holograms are cool.” he said.
“Michelangelo, will you please pay attention.” Chief said sternly.
“Sorry, ma'am.” Mikey backed up to his bros.
“Now then. We've received reports of VILE activity happening in New York. So I sent Ms. Argent here to investigate. And to my relief she found not only Carmen here, but you all as well.”
“What exactly is the nature of your relationship with Carmen here?” Rarity inquired, as the crimson thief answered.
“We have a on and off partnership.”
“Even though we both have the same objective, Carmen here prefers to work her way.” Chief explained.
“Well, everyone does have their comfort zone.” Twilight admitted.
Chief nodded, “Now then, shall we talk shop?”
Carmen decided to divulge, “Well, Chief, VILE is stationed here in New York. They've struck a deal with an enemy of the ninjas and Rainbooms here.”
“Go on.” Chief turned to Leo who continued.
“Our enemy Baxter Stockman has agreed to supply VILE with shipments of mutagen in exchange for not only money but to become one of them.”
“Tell me about this mutagen.”
Carmen answered, “It's an unstable chemical that can mutate the DNA of anything organic that comes into contact with it. Believe me, I've seen what it can do up close.”
“It turned three of VILE's operatives into mutant animal hybrids.” Ivy explained.
“And it's how my brothers and I became what we are today.” Leo finished.
“I see. Then it seems there's more work to be done. Agent Argent, remain in the city for now. And report to us anything that can help.”
“Understand, Chief.” Julia replied.
Chief turned to the group, “Play nice now. And I'll talk to you all later.” the hologram vanished, and the pen fell over.
Twilight picked up the pen, “The technology ACME has is amazing.”
“No kidding.” Donnie agreed.
“Oh, yes. Quite advanced for earth tech.” Fugitoid added.
Carmen looked to Julia, “So, Jules. Looks like we'll be working together again.”
“So it seems.” Julia nodded.
“Can we get pizza now? I'm hungry.” Zack complained.
“Don't worry, I'm all over it.” Keno said, as he headed for the fire escape.
“Care to stick around, Julia?” Leo offered.
“Well, I am quite hungry.” Julia admitted.
Soon enough Keno returned with pizzas for everyone. As they enjoyed their slices, the turtles and Rainbooms were getting to know Julia some more.
“So you and this Chase Devineaux were first on Carmen's trail back in Paris?” Karai asked Julia.
Julia after taking a bite of her slice answered, “Yes. At first Devineaux was recruited into ACME, until I followed a trail of his mints to where he and Chief were discussing about Carmen Sandiego and VILE.”
“So you were let into ACME on a whim?” Raph asked.
“Well, that's one way. But the Chief was impressed my by attention to detail. A lot more than Devineaux ever did.” she sighed.
“Sounds like this Devineaux was a real jerk.” Rainbow said.
“He was very hard to work with due to his ego and failure to pay attention to detail. He was still my partner. And I felt bad when the Chief dismissed him.”
“I just can't believe he's so bad with cars.” Donnie said in disbelief.
“Yeah, even I wouldn't crash a vehicle into water.” Mikey said.
“That's because we don't let you drive so much.” Raph reminded him.
Julia looked to Fugitoid, “Forgive me, Professor. But I just can't believe the ability to embed one's brain into a robot body is actually possible.”
“Well, it is, Ms. Argent. Because if not then I wouldn't be here today.” Fugitoid said.
Rarity inspected Julia's uniform, “I will say ACME certainly has a marvelous uniform. I must know of the tailor.”
Julia smiled, “And I have to say in my research over you girls I have never heard such wonderful music before.”
“Well, we are awesome after all.” Rainbow boasted.
“Yes. You all certainly are.” Julia said, as she scratched Spike's head.
“Well, Jules, hope you're ready for an even bigger team up,” Carmen said, “Especially when you're working with this lot.” she motioned to the ninjas and the Rainbooms who waved.
“It will be an honor.” Julia replied with a smile.
“Oh, yeah. It's gonna be sweet! Booyakasha!” Mikey announced.
Julia tilted her head before looking at Carmen who answered, “It's their catchphrase. Go with it.”
Meanwhile in Stockman's lab, the villainous scientist was at a computer while a giant vat of mutagen was set up. When he heard the door open, he spun around to see Tigress, Le Chevre, and El Topo still as mutants enter.
“Ah, welcome back, you three. How did your meeting with the Faculty go?” he asked.
“It was awkward.” Tigress answered.
“And embarrassing.” Le Chevre added.
“Well, I hope you three are ready to get back out there.”
“We are. But with another plan for now.” El Topo replied.
“What do you mean?” Stockman inquired.
“What he means is, there is something I need to do.” came a voice, as Dr. Bellum entered.
“Dr. Bellum!” Stockman gasped, as he got up.
“I assume you're wondering why I've come here.” she inquired.
“I'll admit I wasn't expecting you. As you can see I'm prepping the mutagen now.” Stockman motioned to the vat.
“Excellent. But until it is ready I have business to take care of.”
“What kind of business?”
“I've come to get reacquainted with an old pupil of mine.” Dr. Bellum replied.