A/n: Merry Christmas, lovelies! Vampire Diaries season 5 is currently on a mid-season break and to fill the void, here's an update!

Chapter 13

When they arrived at the Helicarrier by the Quinjet, Tony, Clint and Thor had already arrived. They were told that Bruce and Eric Selvig were working on a cure to isolate the werewolf virus in the affected people. Natasha and Fury in the holding area, standing before the glass prison that held the hissing alien.

"Amazing." Thor exclaimed, giving the assassin a once-over. "You took on that beast all by yourself? You're a true warrior, Natasha Romanoff."

"It was too easy." she muttered darkly, her suit covered in soot and alien blood.

"Alright. Let's get this show on the road." Tony said loudly, annoyed to have been dragged out of his lab when he was on a deadline to finish the signal tracer. His eyes glanced over at Katherine and shot her a wink.

She rolled her eyes at him and turned her attention back to the alien who lost an arm in the fight with Natasha and continued to hiss at her. "Yikes, you really did a number of it." she deadpanned.

Natasha shot her a look. "I imagined it was you instead."

Katherine sneered before a cough interrupted them.

"Ladies." Fury said, chastising them like a father would. "This guy was spotted three hours ago at the port harbour. He killed one civilian before Agent Romanoff here managed to take him down."

Steve watched the video on a separate screen, noticing how the alien seemed determined to attack the agent rather than fleeing. "No back up?" he asked.

"None. We think the Chitauri are sending out individual ground scouts to bring in more victims as Miss Pierce mentioned."

"Have you tried asking him?" Tony pointed at the alien.

"Do you speak alien, Tony?" Clint asked sarcastically.

"Working on it."

"Oh, he speaks English alright." Natasha said, stepping up to the glass and tapping it. "Hey, pea-brain. Mind telling them what you told me after I ripped out your arm?"

The alien stared at her with inhuman eyes, his gaze slowly drifting over each and every member of the Avengers before pausing briefly on the vampire hanging back. A gurgling sound escaped its throat as its body began to contort, armours and scales melting into tan skin. Fangs shortened, fitting perfectly into the mouth of a man. In human form, he looked like a young man in a plain jeans and a purple shirt. Minus an arm limb.

Natasha inhaled sharply, her eyes narrowing darkly. "That's him." she said softly. "The man it took. I couldn't get to him in time." There was no emotion on her voice. "That's how they have been taking humans. They're inside them and wearing them like a skin."

"Or like how a werewolf changes." Katherine added.

"We'll find a way to reverse the process once this is over." Fury said. "Now start talking."

"You'll never win, humans." the Chitauri said, standing ramrod straight in the middle of the cage. "We're everywhere."

"Details would be helpful." Tony quipped. "Like where your ship is hiding or where the ritual to activate the stones is going to take place."

The creature smiled and a long tongue slithered out. "I'll never talk."

"Maybe you'll like to go a few rounds with our big green friend. Maybe that will lose up your tongue." Fury said, crossing his arms in front of him.

His skin paled and his eyes widened.

Fury smirked. "I thought that might win your cooperation."

It did and in less than a minute, they had five locations worldwide that Chitauri gliders were being positioned at this moment. According to the Chitauri, the leader and the vampire was planning a mass sacrifice all over the globe to draw in the powers of the stones and possibly open up several portals simultaneously. Tony pulled up a holographic visual of the earth, tapping in the locations in red marks: Russia, Argentina, France, China and New York.

"Oh boy." he breathed looking at the globe. "That is…a lot of places to look."

"We deploy immediately. Stark, we'll need to put the tracer on hold until we shut this down. You take Russia. Handle the Soviets delicately please." Fury ordered, looking at the billionaire. "Thor, you head to China. Black Widow, you take Argentina with Banner. Hawkeye, head to France with a team. And Captain Rogers, I need you on ground and on standby here in New York. I'll send word as soon as we have a lead on the location."

Steve didn't like the idea of the team splitting up but knew they had little choice. Innocent lives were at stake. "Yes, sir."

As the team headed out of the area, Katherine hung back, watching the imprisoned Chitauri disguised as a man. He stared back at her, hissing when she drew close to his prison. Slowly she smiled.

Everything was going according to plan.

~.~

Indeed. Everything was proceeding as planned.

What his soldier saw, Zarkis saw and he shared a similar dark smile as the woman in view of his captured slave. A minor sacrifice.

"The Avengers are separating. By tomorrow, New York will be defenseless and my plan will fall into place." he purred.

"I wish you would have told me…of this." displeasure to have been left out was evident in Amanda's tone as she sulked behind him. She had scowled when Katherine had stepped into view.

"You must admit it's a good plan." Zarkis said turning to her.

"And you thought of this, what, today?" she sneered, hands on her hips. "By yourself? I find that hard to take in."

"Had you not been so hell-bent on hunting down Katerina, you would have stayed around long enough for me to let you in on the plan." Zarkis said impatiently. "But it doesn't matter. The Avengers will soon be out of our hair."

Amanda watched the screen, hating how Katherine's smile seemed to mirror Zarkis's. As though she was up to something.

Well, whatever it is, I won't let you play it out.

~.~

Steve waited patiently in the Quinjet for Katherine who had been pulled aside by Tony. He could see them conversing under the shadows of the hanger, him in his Iron man suit and ready to fly out that night itself. A minute later, Katherine broke away from the other man, quickly joining Steve in the plane that would return them to ground.

"What was that about?" he asked.

"Stark is just being an ass." she grumbled.

Steve chuckled. "You're not wrong about that."

They felt the plane take off, the descent back to the city rapid as they sat in silence. Katherine studied the former war veteran, observing the tenseness in his body and the thoughts visible in his eyes.

"You seemed troubled. What's wrong?"

Steve fixed his gaze on her. "It was too easy, getting that information from the Chitauri."

She leaned back in her seat, crossing her arms in front of her. "Maybe Agent Romanoff really did a number on it."

"From my experience, it's never that easy." he said, thinking back to how easy Loki had infiltrated the SHIELD's Helicarrier and in one swoop, nearly killed everyone on board. Or how a supposedly simple retrieval mission in 1943 got his best friend killed.

From the corner of her eye, Katherine could tell that their pilot was eavesdropping judging by the slight tilt of his head. Lowering her voice, she locked eyes with Steve. "If that's what your instincts tell you, Cap, then go with it. Trust what you know."

He gave her a confused look but sensing her apprehension to speak in the presence of another, he nodded, taking her advice to heart. He was sure she would explain later.

The plane docked at the harbour and a car waited to take them back to their apartment to pick up a few things before heading to Stark Tower. They rode in silence until the car came to a screeching stop.

"What the?" Steve shoved the door open, grabbing his shield.

The road ahead was blocked, two over-turned cars laid in the centre and flanking the road were several figures who have obviously been waiting for them and were armed with knives and crossbows.

"Ambush, sir!" the driver shouted, banishing his gun.

"Hold your fire. We don't know what we're dealing with yet." Steve ordered before turning to his companion. "Katherine."

She had climbed out of the car as well, her eyes narrowing on the figures. "Vampires. Amanda's lackeys."

"Alright. Now you can fire." Steve nodded at the SHIELD agent and as guns were fired, he sent his shield spiralling through the air, knocking two vampires unconscious. He shouted over his shoulder as he began moving forward, catching his shield out of mid-air. "Katherine, take cover!"

"Seriously?" she balked.

"I don't have time to argue with you!" he yelled back, punching a vampire in the jaw and slamming his shield into its throat.

The screams of the agent filled the air as he ran out of bullets and the vampires swarmed him. Steve moved as fast as he could but Katherine was there first, effectively snapping the neck of the vampire draining him as she yanked him off the man's body. A second vampire came at her with a stake but she caught it before it descended and pivoting her body, she turned its momentum against its owner and drove the stake into his ribcage. She missed the heart but knew the injury alone was agony. In one fluid motion, she pulled the stake and drove it into the vampire's heart as he screamed in pain.

He barely disintegrated before she staked the first vampire with the broken neck, much to the amazement of Steve.

She winked at him. "Told you I was not as helpless as you think." she said, reminding him again of the first time they met.

He rolled his eyes at her. She has definitely been hanging out too much with Tony. But they were far from out of danger as they suddenly found themselves surrounded and cornered.

"Werewolves." Katherine muttered, her eyes flickering over their assailants. "And…"

"What?" he asked, looking at the group that flanked them from behind. Compared to the vampires and werewolves, this group seemed…off.

One of them lunged at Katherine but she was faster, her hand reaching out to grasp his throat. Her lips drew back as she instinctively prepared to rip out his throat. Without warning, she cried out in pain, pushing the man away as she grasped her arm.

"Katherine!"

"Fuck!" she gasped through the pain, shaking her arm desperately to get rid of the electrical current surging through her muscles. She was going kill Stark for this. But the activation of the bracelet could only mean one thing. "Steve, we've got a problem here." she gritted out.

"You mean on top of what we're facing now?" the head of a vampire went flying as the tri-coloured shield ripped through the air before returning to its owner.

Any other day and time, she could have appreciated his comeback but not today. "These guys are humans, Cap. I can't hurt them!"

"As in Chitauri possessed?"

"No, as in human-human!" she could only dodge and evade as they attacked her. She recognised one of the faces though as their young pilot. Figures. Amanda had an inside man. Somehow she must have gotten to him, compelled him…

A human lunged at her and as she ducked, she felt a prick in the back of her neck and staggered as the ice cold pain of vervain spread through her body. Her body trembled as she grabbed the car hood for support. She could hear someone shouting to hit her again with another dosage, panic evident in their voices.

"Katherine!" Steve shouted in a warning, fighting his way to her as a man ran at her, raising a syringe above his head.

Summoning every last inch of her dwindling strength, Katherine managed to halt the needle's descent, twist the man's hand to force him to release it before slamming his head into the car bonnet. That however earned her another jolt of electricity that made her scream and curse in pain.

"Hang on, Kathe-!"

"Stand down, Captain." a vampire snarled, raising a hand to still the attack. "Put your shield down or every human here dies. Amanda has requested that you two be brought to her alive. I would hate for it to be otherwise."

Steve glanced at Katherine slumped against the car, shaking her head to ward off the effects of the vervain and the electric shock to no avail. He could see the humans slowly approaching her and on the other side, cornering him, the werewolves. He made his decision.

He lowered his shield to the ground and held up his arms in surrender.

"Wise choice, Captain. Amanda will be pleased." the vampire gestured.

Several men stepped forward to retrieve the shield and forced him to his knees. Handcuffs quickly encircled his wrists, securing his hands behind his back. Someone lifted Katherine's limp body and carried her to his side. She was barely conscious and even that was temporary as one of the vampires injected a syringe full of vervain into her neck despite her feeble struggles. Then they injected him too with something that immediately hit his nerve systems.

As the ground and darkness loomed up, all Steve could think about was how he had failed to protect her.

A/n: There has been some questions and inquires in the reviews and I am gonna answer some of them.

This story takes place before the end of season 1, before Katherine's return to Mystic Falls. As such, Klaus or any of the Originals will not be appearing this story nor will Nadia. I am glad that Katherine revealed that she went back for her daughter 500 years ago because it drives the fact that she does have a few people she holds dear and close to her heart (Nadia, Stefan and maybe now, Steve).

Katherine being Katherine does not reveal the extend of her abilities and her importance to Klaus as the doppleganger to the Avengers. If you remember, even to Stefan and Damon, she never told them why Klaus pursued her.

The human KatherineXSteve story is still in the works as I want to see where the show takes the character as rumour has it that she will die in the 100th episode.

That's all for now! Read and review!