"Donnie," Destiny whispers, motioning him to her side. Her fluffy ears are perked, eyes squinted, her body poised just over the edge of the building.

"What is it?" Donatello asks as the other turtles gather in and try to find where she's looking.

"Use your goggles. Check over there." She points to a shadowy spot on the ground.

The intelligent turtle lowers his goggles, spinning them and focusing them. He catches sight of Karai just as she slithers across the street, avoiding the Kraang droids that wander around below.

"What's it look like, Donnie?" Raphael asks.

"She's moving fast. We've gotta get down there," Donatello responds.

"There are Kraang droids everywhere," Destiny whispers with a hint of venom in her tone.

"Keep it stealthy, my ninjas," Michelangelo murmurs with a wink.

"Let's do this," Leonardo orders.

They descend the side of the building, slipping behind abandoned dumpsters and observing the surroundings before they sneak across the street, avoiding the sights of the Kraang. They work like a well-oiled machine, aware of everything and everyone around them at all times. Leonardo, Donatello, and Raphael slip behind a pair of Kraang, making them turn around just before Michelangelo and Destiny can get past. They slip back into hiding.

Donatello turns back once he's safely hidden next to Leonardo, only then noticing the absence of his teammates. "Oh no," he whispers.

"Where's Mikey?" Raphael asks as he drops down behind the blue and purple-masked turtles, sounding almost panicked.

"I'm right here," Michelangelo says as he pops up and smacks his brother's shell. Raphael nearly jumps out of his skin. "You guys are so slow!"

"What about Des?" Leonardo asks, the annoyance lines wiping clear of his face for a moment.

"Already scouting," she says from behind them. They spin around to see her a couple of feet away, waiting for them. "Nice to know you care, Leonardo," she adds, deadpan.

He sniffs indignantly and looks away. "Just checking."

She manages a tiny smile, but hides it in a heartbeat. "Right. Anyways, Karai went this way." She jerks her thumb over her shoulder at the building behind them. "She's in that warehouse."

Destiny turns and moves at a brisk pace to the building, skipping through a broken window. The turtles follow her, emerging into a darkened space riddled with dust and the faint smell of stale wood.

"Alright, guys, let's split up and find her," Leonardo orders as they stare at everything. He cups his hands around his mouth as he starts his own search. "Karai? Are you here? It's us!"

They separate, climbing stairs, checking behind boxes, calling Karai's name. Destiny sniffs the air as she leans against one of the old crates. The smell of snake is still potent, invading her senses and making her feel a little bit queasy. She can't even pick out a direct trail amongst the lingering scents of the turtles and the warehouse.

"Karai, come out! Where are you?" Raphael shouts from somewhere to her left.

"We're not gonna hurt you, Karai. We wanna help," Michelangelo adds.

Destiny massages at her tense fingers, shutting her eyes and breathing deeply. She listens to the footsteps of the turtles, the sound of their voices, the creaking of the metal stairs and supports.

"Karai! Come out," Leonardo pleads above her on the upper level.

Destiny purses her lips and tilts her head upwards, ears swivelling around like solar dishes. Sometimes, she can catch just the faintest sound of hissing, but it's always drowned out by the other voices.

"We'll find a safe place for her to stay," Leonardo says to Michelangelo. The youngest turtle makes no verbal agreement.

"So...what are we gonna do when we find her? Invite her back to the lair for pizza?" Raphael asks.

"That's a good question," Donatello answers. "The retro-mutagen still isn't finished."

Destiny opens her eyes and pushes off the box, taking only a few steps when the barrel of a gun is pressed against the small of her back. Her breath hitches. Donatello and Raphael round a corner and instantly stop in their tracks at the sight of a multitude of Kraang. One droid has the gun against Destiny's back.

"Oh great," Donatello groans, readying his bō staff.

"Another Kraang droid party!" Raphael growls, spinning his sais.

"Take 'em down before they alert more!" Leonardo shouts from the top level.

Destiny whips around and smashes the droid behind her in the face with her elbow, snagging its gun, and shooting it in the chest. Once it's down, she drops the gun and curses, gripping her elbow tightly.

"God freakin—piece of sh—son of a—OW!"

"Kraang, attack the one who is using the profanity," one Kraang droid says.

Before they can make a move, Karai appears in the midst of the aliens. She spins and lunges and twists, striking with precision and deadliness. Each bite from her snake hands takes down a bot and her long arms swat them into pieces with ease. In record time, every Kraang is destroyed.

Karai turns around, coming face to face with Destiny, who's still clutching her bruised elbow. She hisses and narrows her eyes. Destiny morphs into a wolf and towers over the snake, snarling. Karai doesn't back down.

"Des, morph back and let us handle this," Donatello warns, moving towards the giant black animal.

Already on edge, Destiny growls at the advancing turtle and bares her fangs. He steps back with slight fear flashing in his eyes, making her close her mouth and lower her hackles. With a heavy sigh, she returns to her humanoid form as Michelangelo drops down next to Karai.

"It's okay, Karai," he says gently as she turns to him. "It's me. Mikey. Your brother."

She hisses, her slim body waving as her forked tongue flicks.

"Karai, remember us!" Leonardo begs, hopping off the top level and landing before her. "We're your friends. Remember who you are!"

She makes another noise, watching the turtle with venom in her gaze. The hope in his eyes shatters.

"She's becoming more snakelike by the hour. She doesn't understand, Leo," Donatello warns.

"She understands, Donnie," Leonardo insists, shrugging his brother away with a short glare. He keeps his eyes on his sister. "You're changing, Karai. We want to help you."

Her leering features come closer as she hisses in his face. Destiny swallows and inches up to them, her skin prickling. "Leo...let me," she says slowly, her voice barely above a whisper.

She reaches her hand out, making Karai hiss and raise her double-headed hands towards the wolf girl. She doesn't flinch or back down, their almost matching green eyes boring into each other's.

"Karai...please, we need to talk to you," she murmurs, daring another step. "I brought Diaval back, just like I told you I would," she continues, taking a deep, shaking breath. Karai's forked tongue disappears and her slender features soften just slightly at the sound of the archer's name. Destiny's voice gets so quiet that only the snake can hear. "He tried to find you, but...he's in trouble. Shredder got him. I...I don't know what to do to get him back, but you could help."

Karai stares at her for a moment longer. The turtles exchange hesitant glances. One more beat passes before Karai rears back with a throaty hiss. In an instant, her snake form disappears, replaced with an almost human girl with pale skin and green snake eyes. She lays on the floor, her back rising and falling far too fast to be calm, and Destiny kneels beside her. There's a hesitant compassion in her eyes, a kind of emotion that the wolf girl has never thought of giving to someone that she once looked at as an enemy and nothing more.

"Whoa..." Michelangelo whispers. "Destiny's got powers. I wonder what she said."

"Help me," Karai says in a raspy voice, looking up at Destiny. "Pleasssse." Her tongue flicks between her fanged teeth.

Leonardo kneels next to the two of them, his hands up in a defensive position. "Come back with us, Karai," he pleads.

"No," she rasps, sitting up and pulling away from him. "Tooo...dangeroussssss..."

Destiny shakes her head. "You don't have to be afraid of that," she whispers, scooting closer to her slowly. "I know what you're feeling, and I promise you, we can help you. I...I could help you."

Karai watches her, her stance relaxing slightly and a sense of thankfulness crossing her face. Before she can respond, two shapes drop down on either side of the two girls: Rahzar and Fishface. Destiny's eyes narrow and she bares her teeth as she gets to her feet, but she stays next to Karai, one hand reached out protectively in front of the snake girl.

"I told you I smelled turtles!" Rahzar snarls.

"Looks like they've made our job a whole lot easier!" Fishface adds, a grin stretching his fishy lips.

Karai looks to Destiny and bobs her head once. She morphs and hisses at the two enemies, making sure to keep her muscular body shielding the wolf mutant. Fishface wastes no time in whipping out a long staff with a metal collar on the end. He pulls the trigger as the collar claps around Karai's neck. She screams as electricity courses through her and Destiny snaps out of the shock that she found herself in.

"Karai! No!" Leonardo shouts, katanas flashing as he races towards them. His brothers follow.

"Have a whiff of poison, turtle scum!" Fishface calls.

He throws a bomb, immediately catching Destiny in the green gas. She coughs and stumbles, her eyes watering and her senses muted as she almost falls. Leonardo and Raphael stop at the edge of the cloud, arms shielding their mouths as they start to cough.

"Come on! We gotta move!" Raphael shouts, putting a hand on his brother's shoulder.

Leonardo brushes his hand off and holds his breath. He dashes into the cloud and grabs Destiny by the hand, dragging her out of the gas and returning to his red-masked brother swiftly. The team heads up the stairs in an attempt to get away from the poison cloud. Destiny stumbles, coughing heavily as she tries to keep up. Michelangelo starts spinning his nunchucks like fans, protecting his family from the creeping cloud.

"Des, come on, stay with us!" Leonardo says, trying to keep her supported and on her feet.

"You can't...let them...get away..." she mumbles, her eyes squeezed shut and her voice weak.

He frowns and shakes his head, hoisting her onto his shell. With her secure, he takes off after his brothers. They get out of the building just in time to see a motorcycle speeding away down the road.

"Look! There she is!" Raphael shouts, pointing to the unconscious girl on the back of the bike.

"No!" Leonardo cries, but they're already gone.

Destiny lets out a dry cough, curling against Leonardo's shell like a puppy. Michelangelo's forehead creases and he pats the top her head, her body trembling at the touch.

"Dudes, Desti-bear doesn't look too hot," he says, alerting the others back to her.

Leonardo slips her off his shell gently, adjusting his arm around her middle as she tries to plant her feet. Her eyes are dull and she's still coughing, her ears flattened against her curls.

"Donnie?" Leonardo asks, his eyes wide.

"The poison isn't deadly," the purple-masked turtle assures him. "I bet its primary symptoms are coughing, weakness, dizziness, etcetera."

"What do we do to help, then?" Raphael asks.

"Go...without me," Destiny groans. "Save Karai...and stuff. I'll just..." She coughs. "...slow you down."

Leonardo glances to his brothers, every face concerned, and then he looks back down at her and nods. He wraps his arms around her, tucking her to his chest, and although she tenses slightly, she accepts it.

"Be safe," he whispers. She bobs her head up and down once.

Donatello purses his lips. "She needs an antidote. I'll bring her back home and get her rested," he offers.

Destiny pulls away from the embrace only to grip Leonardo's bicep as another bout of vertigo rolls through her. "I'll...take myself home," she says, still holding onto Leonardo like he's a lifeline.

"What if you just make yourself sicker?" Michelangelo asks.

She shrugs. "Then Donnie...can cure me b-back...at the lair." She takes a shaky breath and releases Leonardo, brushing her hair from her eyes. "See...you at...home."

She morphs into her wolf, leaping over the gap between the nearest buildings in the direction of the pizza place. The turtles watch, silent.

"Okay, let's go save Karai," Leonardo says, breaking the silence. The others follow without argument.