A/N: A edited, longer and hopefully better version of the story! First edit.

"I believe you dropped this."

She turns and glares before quickly swiping it from his hand.

Because she never makes mistakes. Especially not during missions like this.

"Wow, Romanoff, who pissed you off? Not even a thanks? Not even two words for Captain Manners?"

"Stark, shut your trap before I shut it for you."

Gulp.

"Oops, looks like she is pissed off."

She barges her way through the crowd of A.I.M. soldiers, yellow suits flying everywhere as she goes on a Hulk-style rampage.

"Woah. How did that happen? I swear there are fucking craters in the ground!"

"Sometimes, Stark, you're better off not knowing."

"Really, Clint? Is this some Soviet secret I am not supposed to know about as well? Because I think-"

"That's the problem Stark, you're thinking with your brain."

"Hey!"

"I was saying that you're better off not knowing the exact power of her wrath."

"Oh."

"Black Widow, are you alright?" Thor booms rather loudly in the enclosed space of the Quinjet.

"Woah, we really need to work on his indoor voice." Tony says. "Tone it down, man, we mortals have fragile ears."

"Yes."

She cracks a small smile but doesn't give anything more.

"Are you certain?"

Involuntarily, she winces at the volume.

Thor murmurs a quiet apology.

"Yes, Thor, I am alright."

She doesn't miss the concerned look Clint gives her.

As the Quinjet lurches forward and spins, they make a rough landing onto Stark Tower.

"Barton! I thought you were an expert pilot?!"

"Blame Thor! There's a hailstorm right in New York!"

"I can indeed summon lightning and thunder, but I do not monitor these things constantly! I assure you, my friends, this was not intentional. I have no power over ice. I am told that is what forms hail?"

"Thanks for the lengthy explanation, but that won't really make up for the turbulence…" Bruce Banner is slightly green-the sick kind-as he walked down the stairs, Thor giving him a friendly hand.

She takes a step, sways, and nearly falls-Steve catching her before she hit the ground.

"Woah, woah, Nat. Take it easy."

The team is at a loss, though only momentarily, as they quickly act out the programmed first aid responses.

Steve sits her onto the ground despite her protests.

And they are all worried at that.

No one can force the Black Widow to do something she doesn't want. At least not without a fight.

Not this time.

Tony scans her and helpfully says that she has a fever but does not have life-threatening temperatures. He goes to take a vial of blood but she panics, spasms, wheezes at that, limbs flailing everywhere, giving Steve a bruised eye and leaving a fist-shaped impression on the ground beside her.

"Okay, okay." Tony backs down slowly with his hands up.

"The testing, remember?" Clint murmurs.

"Sorry." he whispers back. "But I can't tell what is wrong, not without a blood test."

"I can."

They all look at the good doctor.

"Her symptoms are rather distinctive. She has a mild fever, a rash on her neck-"

"Get to the point."

"Has she been to Western Africa recently?"

"No, not in three years or so."

"Well, I have no idea how she got the virus then, since it's a rather contained infection…"

"Well, it was an attack then." Tony decides.

Thor frowns.

"The Black Widow is one of the most careful people I have ever met. I do not believe that anyone can poison her so easily."

"It's the only explanation, unless she got a new job in a level 7 security clearance biolab that I didn't know of."

"I don't think so."

Upon the curious glances, he explained.

"This...poison, bacteria…"

"Virus."

"Virus...whatever it is, doesn't seem deadly or painful. If someone wanted Nat dead, they'd have done something else. If they wanted her to suffer, they'd have done something else. This really doesn't look like anything personal."

"Hey, hey. How about instead of discussing conspiracy theories, we help her first?"

"You know the word conspiracy?"

"It existed back then as well, Tony."

"Barton, since when did you replace JARVIS as the walking encyclopedia?"

They carried her mumbling and fatigued form back to the medical bay as Bruce strapped on different monitoring devices and IVs.

"Her heart rate and breathing are steady and regular, she's just very tired and depleted. I'll be adding some nutrients and vitamins into the IVs, but she should be fine in a few days."

"Thanks, Doctor, it's glad to know she'll get well soon. Is there anything we can do?"

"Well, there's this magic flower in Latvia which grows underground. It's pink with a blue stem and only blooms once a decade."

The team stared at him open-mouthed.

"Geez, with all the jokes you guys make, I'd thought you could take one…" he shook his head. "In all seriousness, there really is nothing we can do. She needs to recover on her own."

When Natasha wakes up a few days later, everyone is relieved.

Well, not everyone.

Tony clamps a firm hand Bruce's shoulder as he vehemently protests.

"When did you become a delivery boy?" he asks, the question clearly pointed at the plate of food in his hand, the fifth he's seen him carry these two days.

"I'm just getting these for Natasha." he explains as Thor looks incredulously at the stack of ribs on the plate.

"Are you certain she will be able to consume so much?"

"Her body size is not proportional to her appetite, Thor, I learned that the hard way. I've never seen her eat this much though."

"How is she?"

"She's fine, just hungry and tired."

"And very moody. She's destroyed three beds, a window and a chair by now."

"I'm sorry, Tony. It's just that-"

"Nah, it's okay." he waves it off. "Just make sure she isn't so hormonal around us, got that?"

"Stark!"

"Apologies, Captain Manners."

Thor looks on, amused, as Tony gives a faux bow.

Tony goes-well, sneaks, into the ward when his scanners show that Natasha has exited her room.

He is curious; and a curious Tony Stark is the second most powerful force in the world, second only to a stubborn Tony Stark.

He has no idea what to look for, but he is pretty sure the teddy bear sitting on her bed is more suspicious than ordinary.

As he takes another step into her room, alarms start blaring and a cage drops right over him.

Seconds later, a pissed off Widow glares at him through the bars.

"Stark..." She hisses.

He shrugs, his face much like that of a child caught with his hand inside the cookie jar.

"What brings you here?"

She makes a show of charging up her Widow Bites.

He knows that, because she keeps them charged all the time.

"We're all worried about you, Nat." He says, his face softening.

"Don't be." She says, turning and leaving.

"Hey, hey! Aren't you going to let me out?"

"I'm going to tell everyone about your teddy!"

She turns back, her face flush with anger and fire blazing in her eyes.

"What. Did. You. Just. Say?" she barked.

"Okay, okay!" Tony pleaded. "I'm sorry!"

She huffed and stomped out, but not before she slammed the door off its hinges.

"Oi, watch it! I have to pay for that! And it's brand new steel!"

The next night has everyone jumping and rushing out, when a seriously bleeding and exhausted, dirt-covered assassin makes her way back to the Tower.

"No offense, but you look terrible!"

"Yeah, yeah. I know."

The casual reply has everyone running for the hills.

"I'm alright, don't worry."

"Natasha?" Bruce probes after a few second of silence.

"What?" she asked nonchalantly.

Clint gives her the don't give me that look.

"Really?"

"I was undercover in AIM."

"And?" Bruce pressed.

At the curious stares, he added, "That virus had to come from somewhere."

"I was there to get intel on a new chemical weapon."

"And you of all people messed up?"

At her glare, he quickly shut up.

"When they tried to use it I had to stop them, but I got exposed."

"Where were you just now?" Steve asked.

"SHIELD just apprehended the rest of them."

"Thank God." Tony says, as Bruce nudges him-painfully-in the ribs.

Clint rolled his eyes.

"Maybe we should focus on her first?"

Thor and Steve haul her off to the medical bay despite her many protests. Now, the kicks and screams and hair-pulling is more comforting than painful.

Bruce takes out a syringe, and this time she does not object as he tests her blood.

Machines start whirring and everyone turns to Bruce for an explanation.

"It'll take a few minutes."

Clint takes in a breath, preparing himself for a long argument.

"We could've helped."

"I know."

"You could've told us."

"Yeah, I could've."

"Why."

"I'm sorry."

What follows is an awkward silence which Thor tries to fill with heroic tales of his childhood, tales of giant monsters and fighting which they have heard to the point of memorisation.

The machine beeps and prints off a few pieces of paper.

Bruce scans them and looks visibly relieved.

"It's really minor now, should be out of your system in a few days. No worries."

"Are you sure? Given how she's been the past few days..."

"Science doesn't lie, Steve."

"I can call upon healers should you need confirmation."

"No thanks, Thor. I think we're doing alright here."

"Yup, the six of us."

"Stark!"

Thor is genuinely confused at the glares Tony is receiving, and being an Asgardian, he gets straight to the point.

"Why are all of you upset at him for stating a mere fact?"

"He thought there would be seven of us."

"But why? I do not understand, Doctor..."

"I'll explain, right after I kill Stark."