Kate falls onto the metal platform below the lab, Nat and Bruce next to her. Up above, she hears Cap shout, "Put on the suit!"

"Yep!" Tony replies.

"Hill?!" Fury asks. Kate, without a comm, hears no reply, but then he says, "Stark, you copy that?!"

"What's he copying?" Kate groans.

"Engine three is down, they have to make repairs outside," Nat replies.

"Coulson!" Fury shouts. "Initiate official lock down in the detention section, then get to the armory! Romanoff?"

Nat presses her comm instead of shouting up at him. "We're okay." She looks at Kate and Bruce, the latter of which is struggling, panting. "We're okay, right?"

"I'm not," Kate replies, finally sitting up so they can get a handle on the situation. Nat's foot is trapped under a beam that fell, and Kate still doesn't have shoes on, her periodic table socks on full display. That's especially great since it looks like she's gonna have to fight again. She sighs. "Where's the stupid comms?"

Nat reaches into her pocket, pulling one out. "Here."

"Since when do you carry an extra with you?"

"It's Clint's."

Kate only nods in understanding before slipping it into her ear and pressing down. "Tony! You need a welder?"

"Let me get back to you on that," he replies, making Kate wince; Clint has his comm turned up to the moon.

"Doctor..." Nat says next to her, reminding Kate of the not so great situation on her other side. His skin is starting to tinge green. "Bruce, you gotta fight it. This is just what Loki wants."

"Are you hurt?" someone calls in the distance. Nat waves them away, and Kate turns to Bruce.

"We're gonna be okay," she says, scooting slightly closer to him. "Listen to me. I get it, okay? I get you, and I know how this feels. But you have to fight it. Push it down — push it down as far as it will go. Alright?" But he doesn't act like anything is alright. "I promise you, we will get you out of this, you will walk away, and never ever-"

"You promise?" Bruce laughs, but his voice changes. It's the other guy.

He gets up, on his knees, skin turning greener and greener. His shirt rips as he gets to his feet and stumbles back, falling off the platform. Kate goes to Nat, who's trying to pull her foot out. The beam is too heavy for Kate to lift, but she still tries, heating up her hands as she does. "I'm gonna have to melt this."

"That's gonna take too long," Nat panics. Kate turns up the heat as far as she dares. Below, they can hear the Hulk replacing the much preferred scientist. Nat pulls on her leg, Kate strains to lift and melt, and, finally, Nat's foot is free.

Instead of running away, however, Nat jumps down off the platform. Kate is about to follow, wondering how much it'll hurt her feet, when Hulk roars. Nat turns and goes straight up the stairs, and Kate meets her at the railing as Hulk rips the stairs from the walkway.

Nat turns and flips over some pipes to the other side of the walkway, and Kate follows her lead, glancing behind them at Hulk. The grated floor hurts her feet, but she doesn't have the time to complain, especially as Hulk tries to rip it out from under her and Nat. Kate scrambles after her, briefly wondering how in the world she does all this so smoothly.

"Stark, I'm here!" Cap shouts, and Kate winces again, still following Nat, getting deeper into the ship. It gets darker.

Tony replies and Kate tries to listen, seeing if she can be of use. "Good. Let's see what we got. I got to get this superconducting coolant system back online before I can access the rotors, work on dislodging the debris. I need you to get to that engine control panel and tell me which relays are in overload position." Kate, during a pause, realizes there is absolutely no way she can help remotely. "What's it look like in there?"

"It seems to run on some form of electricity."

"Well, you're not wrong," Tony replies. "Kate, you available now?"

She presses her comm, replying in practically one breath. "I'm running away from the Green Giant, so no!"

"Crap."

Nat stops in front of her, so Kate follows suit, breathing the only noise until Hulk's booming footsteps sound overhead. She feels like she's in a horror movie, and she is not looking forward to the jump scare. Nat glances back to her. "Now would be the time to whisper."

"Are we gonna keep hiding?" Kate asks. "Or are we gonna try to take care of it? I vote for option one."

In answer, Nat pulls out her gun and turns back around, heading for a path through the maze of pipes and equipment. Kate sighs quietly but follows, knowing it's probably her best option. She doesn't want to meet Hulk alone.

They move quietly, looking around, listening. And then the jump scare comes.

Hulk roars, appearing in front of them, and Nat shoots a pipe above him, the concentrated air shooting out. He slams his head into the pipe as Kate and Nat turn and run down a long hallway. Hulk follows them, breaking the surrounding glass that Kate hopes she won't step on. She glances behind her. His closeness causes her heart to leap, and she makes a fireball, chucking it at him. It gives him pause and at least a bit of pain, but mostly serves to make him angrier.

At the end of the hall, Kate's knocked off her feet, flying and getting knocked against the wall. Pain flashes through her back. Hulk stands across from her, while Nat is to her left, turning to face him, aiming her gun. He pays no mind to her, approaching Kate instead.

"And this is where I die," she breathes, lighting up. His hand raises to backhand her.

A streak busts through the wall, tackling Hulk and probably saving Kate's life.

They break through to the hanger, and Kate can see that, unsurprisingly, it's Thor. He's on his knees, holding back Hulk's fist. "We are... not your enemies, Banner! Try... to think!"

"Better him than me," Kate mutters, extinguishing and looking at Nat. They turn back in time to see Hulk punch Thor through a stack of plastic boxes. Kate scoots back as far as she can, not wanting him to turn back to her. He roars, instead searching for Thor.

Kate hears Cap's voice on comms. "Okay, the relays are intact! What's our next move?"

"Even if I clear the rotors, this thing won't re-engage without a jump," Tony replies. "I'm gonna have to get in there and push."

"Well if that thing gets up to speed, you'll get shredded!"

"That stater control unit can reverse the polarity long enough to disengage maglev and that could-"

"Speak English!"

"See that red lever? It'll slow the rotors down long enough for me to get out. Stand by it, wait for my word."

Kate turns back to the Hulk situation, which Nat has also neglected to get involved in. They hear a small crash, the distinctive sound of Thor's hammer, then a blow being dealt. Nat creeps forward, and Kate, aching all over, pushes herself to her feet. They see Hulk landing on a plane, crushing it likely beyond repair. That also serves to make him more angry, and he rips the wing off the plane and throws it at Thor.

Evidently they play limbo on Asgard, because Thor drops and dodges it expertly, sliding on his knees. He gets up when the danger's passed, throwing his hammer at Hulk, who attempts to catch it. And, technically, he does, but it still takes him to the ground. He can't even lift it, but tries, digging his feet into the floor. Without thinking, Kate moves closer, brows furrowed.

Even Hulk can't lift it? Why? Come to think of it, Thor never explained why he couldn't at first.

Thor kicking Hulk and retrieving his hammer distracts her from her thoughts. Her eyes widen when she sees Thor going behind Hulk and pulling the handle of the hammer across his neck. A chokehold for a giant.

"Well, I was gonna ask if you thought he needed help," Nat comments as Hulk leaps through the ceiling, trying to get Thor off.

Kate shrugs. "Maybe later."

"We've got a perimeter breach," Kate hears on the PA through the sounds of the fight upstairs. "Hostiles in SHIELD gear."

"How are we supposed to know who the hostiles are?" Kate asks.

"Whoever's shooting at you," Nat replies. "Come on, let's go check on Thor."

Kate follows her into the hanger, cautiously approaching the hole in the ceiling, where they can still hear a fight raging. It moves further from them, and Kate turns, spotting a small plane facing the Helicarrier through the window. There's banging upstairs, but then the plane starts firing and the noise stops, and Kate holds her breath. Then, glass breaks and Hulk roars, jumping onto the plane. He rips parts out of it, and it starts spinning towards the ground, taking him with it.

Nat stands next to Kate, watching the plane descend. "On second thought, Thor's probably fine now."

"Probably," Kate replies, though they don't hear much sound from upstairs.

Nat sighs. "Look, this might be a bad time, but I'm sorry."

"Yeah, I know."

"I didn't know exactly what was going on, what the plans were to protect against alien threats. I didn't know your research was directly part of that, and Clint didn't either. But maybe we should've guessed that."

"Maybe I should've, too. I was the one doing the research."

"I'm sorry for not telling you anything."

"You haven't been here."

"But still."

Suddenly, the ship starts tilting to the side, causing them to stumble. Kate looks at Nat with wide eyes. "We just lost another engine."

Fury's voice comes over comms. "It's Barton. He took out our systems. He's headed for the detention level. Does anybody copy?"

Nat presses her comm, still looking at Kate. "This is Agent Romanoff. I copy."

"It's Kate," she answers. "I also... copy." Nat gives her a look before heading to the detention level. Kate sighs, following, stepping around debris. "Scientist, not a spy."

As they go, Fury continues. "Stark, we're losing altitude."

"Yeah. Noticed," Tony replies.

Kate continues with Nat, the walk a short one as they spot Clint up on a walkway, his back to them. Nat gestures ahead, mouthing, 'Get in front.' Kate nods, sneaking underneath the walkway and looking for the stairs. A few moments later, there's fighting above her. She rushes, not worrying about being quiet, finding the stairs and running up them. She turns onto the walkway, watching as Nat slips under it. Clint goes to follow, but Kate throws a small fire ball above him to get his attention.

It works.

He turns, quickly drawing his bow, aiming at her. But the last time he pointed a weapon at her, he never fired; his hand shook, like it does now. "Clint, put it down!" Kate shouts, willing herself to walk to him, her hands at her sides but unlit. His electric blue eyes look into hers, his brow furrowed in concentration.

Nat swings up and around a pole holding up the walkway, kicking him, making him stumble back. He shoots low, and Nat swings around another pole, dodging the arrow even though Clint never misses. Kate smiles a bit, running up behind him, grabbing around his shoulders, restraining him. He jerks, pushing back, but Kate hangs on for dear life until he moves to slam his head back into her face. So that's what she should've done.

She lets go, slipping around him and taking out his leg in the process. He hits the ground but pops back up quickly, swinging his bow at Nat as she comes at him. She throws her arms up to block, and he hooks the bow string around her arms and pulls forward, slamming her hands into her face. Kate meets his back, getting her arms around him again, this time grabbing the bow. The only problem is, she can't see what she's doing.

However, it does force Clint to worry about Kate instead. He jerks again, so Kate twists the bow upright and pulls him back, then slips in front of him. Nat gets her arms free.

Kate throws a punch, and he dodges, again using his bow to swing at her. She side steps, kicking his exposed side, hitting him back against a pole. "Ow!" she exclaims, her foot smarting from the blow.

He lifts the bow again, but Nat grabs it, pulling him towards her and forcing Kate to move. Nat twists, and Kate kicks Clint again. His hand slips from the bow, allowing Nat to use it instead. But of course Clint has more than one weapon.

A knife.

Kate's eyes widen. He may not try to go for a killing blow, but any injury with that won't be good. She reaches for his wrist, but he's ready, moving out of her grasp. Nat, on his other side, distracts him with a blow before he can fight Kate again. She tries to think, going over training, anything, to end this situation as quickly as possible.

Clint is still in there. But what — or who — is preventing him from taking back over?

Kate lights up, the fire starting small in her left hand. Nat sees it first, shooting Kate a confused look before dodging Clint's knife. He turns farther than he anticipated, and the fire catches his eye. He looks at her.

"Loki," she says, willing her voice not to shake. She tosses the fireball to her right hand, back to her left. "Can you see this? Can you hear me?" She starts threading the fire through her fingers, making it dance. Clint watches, the fire reflecting in his unnatural eyes. "He's expendable to you, but I know where you are. You think the Black Widow can't handle him by herself? She doesn't need me-"

Nat cracks Clint across the back of the head with the bow, and he snaps out of it, turning, but she grabs the back of his head, slamming it into a pole. He slumps to the ground, still conscious but struggling to get up. On his knees, he looks at Nat. "Natasha...?" Kate, becoming hopeful, shifts to see his face, but he turns to her first. "Kate...?" His eyes are darker, but still an unnatural blue.

Kate punches him, knocking him out cold.

Nat looks at her. "Nice."

"Thanks, you too."

"All hands to crash stations immediately," the PA says.

A few moments later, the ship seems to be righting itself, throwing Kate and Nat off balance again momentarily. Tony's voice comes over comms. "Cap, I need the lever!"

"I need a minute here!" Cap replies.

"Lever, now!"

Kate, not even believing she can make it, starts moving to them. Nat doesn't follow. "I wanna make sure he doesn't wake up and go all Loki again."

"Good idea," Kate replies, running off, wincing at the metal floors on her feet again. As she hurries up the stairs, she hears Fury's voice. "I need medics at Hulk's cage! Coulson-"

Forgetting Tony and Cap, she changes directions, running faster than she thought possible, soon tearing into the room where Coulson is slumped against the wall, blood on his chest and mouth.

"No, I'm clocked out here," he says.

Fury is crouched in front of him. "Not an option."

"It's okay. This was never going to work... if they didn't have something to-"

"Coulson!" Kate forces, breathing hard. She moves next to Fury. "What happened?"

Coulson weakly reaches out, trying to push her away. "Kate, get out of here."

"No! What happened?"

He sighs. "Loki."

She lights a small flame in her hand, reaching over and forcing Fury to move away. "Maybe I can cauterize-"

He puts his hand on her wrist, forcing her to put the flame out. "No. No, please, don't."

"But it might work!" she argues, chest heaving.

"Kate, it's too late."

She can't accept that — she can't. She grabs his hand, squeezing it, willing him to stay, fighting against everything to keep him here even as helplessness crawls in to overtake her. "I can't lose you, too." His face becomes blurry through her tears, but she can still see his soft smile.

"It's okay, Kate. It's all gonna be okay."

She shakes her head, sobbing now. "No, it won't."

"It's gonna be fine," he insists, voice now a whisper. "You can do this, Kate."

"Not without you."

"You don't need me." His breathing is labored now. "You have a team."

She squeezes his hand again, blinks away tears. "Of course I need you." She only wishes she'd said it before now.

That soft smile still rests on his face, his eyes sad and gentle and comforting. "But not anymore. You've grown, Kate. I'm so proud of you." He attempts to squeeze her hand back. "So, so, proud..."

Kate struggles to breathe, wishing this was all a dream, that he wasn't slipping away, leaving her. "Coulson..."

He takes in a breath, the smile almost humorous now. "I'm leaving... my trading cards... to you, okay? Take good care of them..."

"I will," Kate promises, squeezing his hand once more. His smile starts to fade, his eyes slip to the ceiling. He exhales, a light leaving, and Kate panics, shaking him. "Coulson? Coulson!"

The medics run in, two of them with a bag, and Kate looks at them, still holding his hand. "Hurry! Help him!" They look at Fury, then crouch next to Kate, examining the wound, and she can't just sit there and do nothing. "What can I do?"

A medic turns to her. "Just stay out of the way."

She scoots to the side, not letting go of Coulson's hand, even as hers warm up. "What can I do?" The medics don't answer, working. Coulson still hasn't inhaled. "Coulson?!"

Suddenly, Fury's hand is on her shoulder, his other on her wrist, pulling her back. "Kate..."

She whirls around, jerking out of his grip, getting up, her hands sparking. "You lied to me!"

He puts his hand on her shoulder again, leading her out, then blocking the doorway. "You know I keep secrets."

"This is different! This isn't secrets! You had me doing your dirty work and didn't even tell me what I was doing! You said you trusted me, and yet you kept something like this from me?!"

"You're saying you would've passed up the opportunity to learn something just because of what we were using the research for?" Fury asks, pausing to let it sink in. "I knew that would be a hard choice for you. I made it easier."

"Don't you dare act like you did any of this for me," Kate spits, clenching her hands as she storms away.