"Guys, I'm sorry."

Raphael stops punching the lair's resident punching dummy, shoulders heaving, teeth gritted. Whether it's out of anger or exhaustion is a toss-up. Michelangelo looks up at Leonardo and Destiny from where he sits on the living room bench, swinging his feet idly.

Destiny nods, bowing her head. "I'm sorry too."

"We should've told you what we were up to," Leonardo says. He pauses, looking between his brothers, taking in their silence. His shoulders droop. "I know I...probably don't even deserve to lead this team after what I did."

Raphael scoffs, shooting his brother a glare before crossing his arms and turning away again.

Leonardo purses his lips, catches Destiny's eye, and takes a deep breath. "Karai isn't going to stop," he says. "I know we all wanted more time. We wanted to plan and find allies and figure out what we're doing but Karai won't wait. We need your help now."

The silence lasts for a few agonizing seconds. Michelangelo stares adamantly at Raphael, while Raphael still doesn't look at his brother. The message is clear. Michelangelo is following Raphael's lead this time.

"Okay," Raphael says, finally uncrossing his arms. Leonardo and Destiny's shoulders slump and Raphael aims a finger at them, making them tense back up. "One more mission. You guys were right about one thing; I'm pretty tired of fighting for every second of peace I get."

----------

When the doors to Shredder's throne room, Karai is again perched on her throne while Shinigami sits on the stairs near her feet, playing with a black cat. Leonardo and Destiny enter first, Leonardo still dressed in his black vigilante gear, and Raphael and Michelangelo come in behind them.

"Leo, Des, I didn't think you'd make it," Karai says, head perched on her hand. Shinigami lets her cat hop out of her lap and Karai sits up, face softening. "How's Donatello?"

"He'll be fine. He's a tough turtle," Raphael says.

Shinigami's cat trots up to them, weaving between Michelangelo's legs, and he stoops to pick it up. It meows as he cradles it in his arms, looking up at the girls.

"Hey, Shinigami. What's this little guy's name?" he asks.

"Shiro," Shinigami answers. She giggles and waves her hand through the air. "I enjoy the irony."

Karai gets to her feet and things get quiet again. She moves down the stairs, stopping a few feet ahead of the turtles and Destiny before she snaps her fingers. Four mousers, all lingering around the throne, open their mouths and project a hologram into the air, revealing a video of some kind of factory.

Immediately, the turtles are more on edge. The robots are nearly identical to a Kraang Foot bot design from a few years back, one that resembled Chris Bradford's human form and was programmed to capture April. Destiny tilts her head, brow furrowing in confusion.

"We underestimated Tiger Claw's army," Karai says. "There's no telling how many Foot bots he has. We need to go after the source."

"A Foot bot factory?" Raphael repeats. "Are you crazy?"

Leonardo shoots him a glare, but Raphael just shakes his head and aims a challenging glare right back.

"It'll be worth it," Karai insists. "Without soldiers, Tiger Claw doesn't stand a chance at taking back the city. It'll be that much easier to get rid of him and all the others for good."

"You make it sound easy," Raphael scoffs. "These guys are like cockroaches. You think you've smashed 'em but they keep coming back!" At the thought, he shudders to himself.

Karai smirks, hand on her hip. "I thought you liked a challenge, Raphael," she says.

Raphael growls and starts forward, but Leonardo lifts his hand and stops him. He keeps his attention on Karai. "Raph's right," he says. "This is a big risk, with no chance at permanent pay off."

Karai's golden eyes glitter as she moves closer to Leonardo. "That's what you think. I'm willing to do what it takes to make sure this ends," she says, and Leonardo's eyes widen in realization.

Destiny, having been standing in stoic silence for the whole exchange, suddenly moves as if animated back to life. She steps between Leonardo and Karai, teeth bared.

"You can't do that," she says.

"Why not?" Karai retorts. "It's the next step. Shredder was the first, now it's their turn."

"No," Destiny repeats.

"I'm sorry, I wasn't asking," Karai snaps. Her laidback smirk disappears and she's suddenly so much colder, so much harder to reach. "Don't act like you're above this. You know as well as I do that the only way to get rid of Shredder was to kill him."

She hisses the last words and Destiny's lip twitches, hand spasming as she suppresses a flinch. Behind her, she hears Leonardo suck in a sharp breath.

Karai looks past Destiny, eyes burning. "There's blood on your hands, Leo. You have a choice. End this, for good, and come with me..." She sweeps by Destiny, leaning close to Leonardo, and she bares her teeth in a half-smile. "Or not."

Leonardo closes his eyes, sucks in a breath, and pushes her away from him. She inhales sharply and he shakes his head.

"Sorry, Karai, but this is where I draw the line. We'll stop you if we have to."

Immediately, the tension in the room skyrockets as Foot soldiers stand and unleash their weapons. Shinigami gets to her feet, readying her crescent blade as two more soldiers drop down on either side of Karai. She holds her hands out to them, pausing an impending attack, and turns. She waves her hand at them, sighing.

"Have it your way," she says.

The Hamatos barely register that she crushed something in her fist before she whirls around, hurling a smoke bomb at the group. Destiny shields her eyes as the turtles cough, stumbling away from the burning vapour.

Destiny growls and hurries forward, reaching for her sword, but Shinigami laughs and releases a wave of bats from her cloak. The bats swarm the turtles and Destiny, nipping and swatting at them with so much fury that it steals all their attention. By the time they fight them off, turning them back into clouds of sparkling dust, Karai, Shinigami, and their Foot soldiers are long gone.

"Well, that was a great plan," Raphael says, rolling his eyes.

Michelangelo groans, pushing himself up. "Shiro's gone too..." He sniffles. "Double the lame."

"What now?" Destiny asks. She grips the hilt of her uchigatana. "Leo?"

"We go after her, obviously," Leonardo replies, turning back to the door. "Ninjas, let's move."

----------

There's no time to get backup. They aren't even sure where to go and would be entirely lost if it weren't for Destiny's nose and the tracker on Karai's phone. Without Donatello or Sarina on hand, it isn't as fast, but they figure out where she is and, simultaneously, where the Foot bot factory is.

"Alright, this is it," Leonardo says as the map appears on-screen, directing him.

Raphael moves to the front of the car, dripping onto one of the straps left behind from the ShellRaiser's subway car days.

"I still can't believe you and Des were working with Karai behind Splinter's back," he says.

"You don't have to rub it in," Leonardo mutters.

"Just saying," Raphael says. He gestures to himself. "That sounds more like me. Remember when I wanted to dress up as the Nightwatcher vigilante, and you talked me out of it?"

"What? When did that happen?" Destiny asks.

"Oh, that was when you were off in Canada," Michelangelo pipes up. "Raph was gonna quit the team and go solo."

"But...I didn't," Raphael reiterates. "Leo talked me out of it."

"Hey, you can always be Turflytle's faithful sidekick, Maggot Boy!" Michelangelo says with a laugh.

Raphael's eyes narrow, he walks back towards Michelangelo, and gives him a solid bonk on the head. Michelangelo yelps, rubbing the spot as he pouts up at him.

"Geez, been a while since you did that," he says.

"You haven't been as annoying lately," Raphael returns. He wiggles his fist. "Don't go testing me."

"Roger that, Raphie, good buddy." He dodges a second swipe from Raphael, pouting again. "Hey..."

"Only Tay gets to call me Raphie."

"Raphie," Destiny whispers, and Raphael bristles as he slowly looks at her. She gives him a shit-eating grin. "Ha, I'm not dead."

"Yet..."

"Children, children! We're almost there!" Leonardo calls over his shoulder. He shifts the ShellRaiser and steps on the gas.

----------

By the time Leonardo, Michelangelo, Raphael, and Destiny arrive at the Foot bot factory, Karai has been chained up along with all her soldiers. They stealth inside, just able to see Tiger Claw, Rocksteady, and Bebop guarding their prisoners. If it were just them, it'd be easy, but the legion of Elite Foot soldiers makes this a lot harder.

That doesn't even touch on the fact that the factory employs the use of melted iron and steel so hot that it burns like lava. The pool below the thin walking paths bubbles and shoots steam into the cavern. It's so hot that they're already starting to sweat.

Leonardo stabs his katana through an Chrome Dome's chest, slicing it down the middle. As it clatters to the ground, Tiger Claw turns to face them.

"Let them go, Tiger Claw," Leonardo orders.

Tiger Claw smirks, a low growl leaving him. "I can always count on the heroes," he says, raising his laser rifle.

Bebop and Rocksteady race forward, unleashing their own attacks as Tiger Claw's bullets rain down. Leonardo deflects the laser bullets as Raphael and Michelangelo split off to take on the others. Destiny soars over Leonardo's head, heading straight towards Shinigami and Karai.

As she works on getting Shinigami's chains off, one of the Elite's cone-shaped hats makes quick work of Karai's bindings. Leonardo drops down beside them, helping Karai to her feet.

"Seems like we're making a habit of rescuing you lately," he comments.

"Well, if you could show up, like...five minutes earlier!" Karai retorts.

Destiny frees Shinigami. "We'll keep that in mind for next time," she says.

"Look out!" Shinigami shouts.

Destiny ducks as Shinigami catches an Chrome Dome's laser whip around her wrist. With a powerful leap, she launches over its head, wraps the whip around its throat, and decapitates it. The bot drops into a pool of its own oil.

"Brutal," Destiny says with a sharp grin. "Nice move."

"Just try to keep up, okami," Shinigami retorts, dashing off into the fight.

Raphael and Michelangelo free the remaining Foot soldiers with a few quick swipes. Even with everyone free, the Hamatos and their allies find themselves horribly outnumbered. For every bot they cut down, three more appear.

"I can't believe we're helping Foot soldiers fight Foot bots!" Raphael hollers as he stabs and slices whichever robot gets too close.

"I know! So weird!" Michelangelo agrees.

"We've got to shut down this machine or we won't stand a chance!" Karai shouts.

Raphael rushes to the control panel, desperately mashing buttons as he tries to shut the machine off. Michelangelo and Leonardo tag-team to use Rocksteady's brute strength against Chrome Domes. Shinigami distracts Bebop and Destiny flies just out of reach, doing her best to keep Tiger Claw away from Karai.

"STOP. MASHING. BUTTONS!" Karai yells to Raphael as he punches the control panel.

"Hold on, I've almost got it!" Raphael retorts. The machine seems to speed up. "Okay, maybe I don't got this."

The battle takes an unfortunate turn. Karai's foot soldiers fall, overwhelmed by the Chrome Domes. Leonardo and Michelangelo find themselves cornered on a thin platform, high above the boiling lava pit. Shinigami struggles against a glob of Bebop's glue, pinning her to the wall. Backed into a corner, shell against the control panel, Raphael gulps. Destiny flies at Tiger Claw, but he grabs her by the stalk of her wing and throws her aside. She hits one of the robot moulds and just manages to grab on before she falls, her wing throbbing.

"There is no escape for you!" Tiger Claw bellows as he hovers in front of Karai.

Karai runs, leaping up the unused moulds to the melting pot at the apex of the roof. She plants an explosive just as Tiger Claw clips her shoulder with a laser bullet, knocking her back. She slips down the side of the pot, duffel bag of explosives at her side, and Tiger Claw lands before her.

"Wrong move," he growls, aiming his pistol at her. Karai reaches for her belt and Tiger Claw's eyes narrow. "What do you think you're doing?"

Karai grins, lifts her hand, and presses the button. "This."

"NO!"

With a mighty boom, the explosives planted all around the room go off. Karai and Tiger Claw plummet. Karai hits the wall and crumples, lifeless, as Tiger Claw screams. Pieces of factory equipment fall into the fire below, splashing molten metal onto the Chrome Domes, destroying walkways, and causing the entire structure to shudder with the sudden stress of the damage.

"Ninjas, move!" Leonardo shouts.

"Stop them, you fools!" Tiger Claw roars.

Leonardo retrieves Karai, gathering her in his arms before disappearing after the others.

----------

Sirens scream in the distance, en route to the pillar of smoke where the factory used to be. The turtles, Destiny, Karai, and Shinigami touch down in an alleyway.

"Let me see," Leonardo says, reaching to examine Karai's face.

"I'm fine."

Karai pulls away from him, putting some distance between them as she gingerly touches the burns lining the side of her face and neck. She closes her eyes, clenches her fist, and her skin shifts into silvery scales. After another second, she sheds them, revealing only raw, reddened skin where the burns once were.

"Woah," Michelangelo says.

Leonardo's eyes narrow. "I told you it was dangerous."

"I told you that I was fine," Karai replies coolly.

"Guys, save it for later," Raphael says as he lifts a manhole cover.

Shinigami sweeps to Karai's side, leading her towards the hole with barely a touch on her elbow. The couple disappears into the sewers, followed closely by Michelangelo and Destiny. Raphael gestures Leonardo forward and, with one more shared look, they too disappear.

----------

As the group hurries into the lair, Destiny halts for a second. Her ears perk, flicking a bit, and she starts to smile.

"Guys," she says.

The brothers share a quick look before they dash off to the dojo. They fling the sliding screen door open, finding Donatello sitting up on the tatami mat, Sarina and Splinter at his side.

"Donnie!" Michelangelo cries.

"I'm okay," Donatello says. All four mutants run towards him and his eyes widen. "W-W-Wait! Don't touch me—" They dog-pile him with hugs, flattening him, and he groans. "O-Oh, ah...I'm hurting..."

"All of you, please," Sarina chides, a loving smile on her face.

"Sorry, Don," Destiny says, half-laughing as they untangle themselves from the pile.

Michelangelo, Leonardo, and Raphael can't stop grinning and laughing at Donatello as he slowly sits back up. Michelangelo pinches his cheeks and Donatello doesn't have the energy to bat him away. At the entrance to the dojo, Karai appears, smiling softly at the scene.

Splinter rises to his feet and greets her. "Miwa."

"I'm sorry, father," she says. "I'm glad Donatello is alright."

"Now you see the pain and suffering revenge causes," Splinter says.

"I know," she replies. She turns away from him, squaring her shoulders. "I thought I could make this about taking down Shredder's remaining assets, but now I see that that will never be enough. It's too much of a risk."

The laughter dies out as the turtles, Destiny, and Sarina turn to listen to Karai.

"I promise, I will no longer go after his possessions." A pause. "I'll go after Tiger Claw, the recruits. Everyone left still willing to carry out Shredder's legacy."

"Wait, Karai—" Leonardo starts, alarm painting his features.

Karai turns, hazel eyes blazing with certainty. "I won't do it right away. I need to train my men, get them ready, but I don't want any of you to worry," she says. "You did the hard part. I'll do the rest."

She leaves before any of them can say another word.