A/N So this is my first attempt at writing an Avengers fanfic, and it kind of spawned from an idea that came up during a conversation with the wonderful Klyntaliah! Go and check her out if you haven't already, she's fabulous (but beware the feels!).

It's been a while since I've written and this is also the first time I've ever written a fight scene, so I apologise that it's not brilliant!

It all happened so suddenly. One moment they were all sitting around the table in Stark Tower speculating and laughing about Thor, who had finally gone on his first real 'human' date with Jane. He had left an hour ago, dressed in a black suit Stark had called in a favour for, and somehow they had managed to persuade him that he really didn't need to take Mjolnir with him. Then, before they knew what was happening, they were on the floor, sent flying by a blast which had shattered the glass wall.

Natasha Romanoff coughed as she pushed herself up, taking a moment to gain control of her breathing before she stood. Around her she could make out the six shapes of the others, noting quickly that no one seemed injured and that they were all on their feet as well. Confused glances were exchanged between them, before a large shape flew in their direction, coming to land in front of them.

It, whatever it was, stood on two feet, it's posture hunched as it surveyed the Avengers, who in turn took in the dark, scaly grey skin of the creature and the thick spiked tail that lay on the ground behind it. None of them knew what it was, but then it didn't really matter – it posed a threat and so they would deal with it.

"Where is the mind stone?" It demanded, it's voice gravelly and somewhat hollow. It was a testament to their professionalism that not one of the Avengers looked in the direction of Vision, instead keeping their eyes fixed firmly on the intruder.

"The mind stone?" asked Tony, stepping forwards. As ever, he was the one to take charge. "I'm afraid we can't help you there. We don't know anything about a mind stone."

"Lies!" The creature roared, though the team stood their ground. "It is here, in this very room! And I shall tear this place apart unless you give it to me!"

"Well then tear away," Tony shrugged. "Like I said, we don't know anything."

In all fairness, it wasn't that much of a lie. They all knew the mind stone was a thing, and where it was, but they didn't have any idea of what it did. All they knew was that it was safer in their hands, or rather Vision's forehead, than anywhere else.

The creature roared again, and suddenly four more creatures, the same but slightly smaller, flew in and landed either side of the one that was clearly in charge.

"We'll give you one last chance, humans." The first one hissed, eyes sweeping round to catch all of them under its glare. When it received no reaction, it roared a third time, and the room erupted into chaos.

They were big, and as they moved it was clear to see the strength in their legs and arms, but what they had in size and strength they lacked in speed, and Natasha was easily able to dive out of the way as one of the creatures launched itself at her with bared claws. She was back on her feet quickly, whirling to face the creature which squared itself up to her. They stood like that for a moment, Natasha almost daring it to make the move. When it did, she dropped to the ground and rolled under it as it leaped. If she had been prepared for the attack, she may have slashed at it with a knife, but the team had not expected anything to happen tonight and so had no weapons to hand. She would have to toy with the creature for a while; if she got to know it's fighting style, she could use that against it.

And so it went on; the creature lunging and leaping at Natasha who deftly avoided its snapping jaws and swiping claws. Her earlier assessment of its lack of speed proved right, and she found that the size of the creature meant it was unable to stop itself quickly to turn and face her again. A plan quickly formulated itself in her head, and she began to lead the creature around the room in what could have been an elaborate dance routine. As she moved, she caught glimpses of the rest of the team. Tony and Steve were taking on the first creature, the leader, together. Sam was doing what he could to avoid the creature he was facing, whilst Wanda was using her magic to throw objects into another creature's path – Natasha assumed the witch's magic had not worked on the creature itself. Clint was also moving around the room, evading attacks as he attempted to reach the weapons store. Vision was the only one not present, for which Natasha was glad. His job was to protect the mind stone, and right now that meant keeping it away from these creatures.

She had reached her destination now, and stood in the corner where two solid stone walls met, waiting. The creature faced her, its mouth twisting into a sickening grin which showed yellowed fangs. It thought she was trapped. As it launched itself at her once again, it out a roar as if acknowledging the triumph it believed it had. At the last second, Natasha dropped, rolling out of the way and allowing the creature to crash into the wall instead of her. She stared at its now still form as she got to her feet, watching it for a moment to ensure it was defeated, and then turned, ready to help the others.

Suddenly her legs were swept out from under her, the creature having used the last of its energy to swing its tail along the ground. Natasha landed on her back with a thud, her head also colliding with the hard wooden floor. She groaned as she started to push herself up, only to see one of the creatures heading towards her. In her peripheral vision, she could see Sam lying in a heap near the bar.

She went to stand, wincing as a jolt of pain ran down her spine. She gritted her teeth as she forced herself to her feet, but she had been upright for barely a few seconds before this second creature lunged at her. It was no faster than the first creature, but the pain in her back slowed her down, and she found herself on the floor again, this time on her side. She took a second to catch her breath before she rolled onto her back, wincing at the pain before she pushed herself into a sitting position. The creature stalked towards her, and Natasha found herself pushing herself backwards, thankful that she knew this room like the back of her hand. Of course, that was when the room was put together, without the furniture scattered all over the place from both the blast and Wanda's magic. In the state it was in now, Natasha found herself with her back to what felt like the top of the table they had been sat around not long ago. Now she really was trapped, she realised, as she watched the creature advance towards her, grinning the same sick smile as the last one.

Out of the corner of her eye, she could see Clint getting backed into a corner by two of the creatures, Wanda having exhausted herself and collapsed. The Red Room had taught Natasha that she must never feel fear in the face of danger, and yet, in that moment, she was afraid. Not for herself, but for her friend. He was outnumbered, and Tony and Steve were still busy trying to take down the first creature. Natasha looked back at the creature which stood over her, taking its time, knowing it had its prey trapped. She glared up at it, feeling her fight return to her. She slid one hand across the ground, keeping her eyes fixed on the creature as she attempted to find something, anything, she could use as a weapon. At last her fingers closed around something, and just as the creatures face came close to hers, she pulled her arm around and hit it over the head, managing to roll out of the way before it could fall onto her.

She pushed herself to her feet then, vaguely aware that the pain in her back seemed to be diminishing, and threw the object in the direction of the creatures that had Clint cornered. It was only as it flew from her hand that she realised what she had managed to grab, and her eyes widened as she watched it fly through the air.

Once, before Ultron, there had been an evening when all the men on the team had tried to pick up Thor's hammer, each of them failing as Thor laughed and deemed them not worthy. Natasha had declined to take part, not needing the answer to the question of whether she was worthy or not. She knew she wasn't. There was too much red on her ledger.

And yet, in that moment of desperation, as she feared more for the life of her best friend than herself, she had lifted it and wielded it.

She held her hand out as Mjolnir collided with the head of the first creature facing Clint before rebounding onto the head of the second, and then flying back into her hand. She stared at it for a moment, before her professionalism took over and she threw the hammer at the last creature standing – the one facing Tony and Steve. It hit the creature on the back of the head, right in the hollow where the neck met the skull. It stilled suddenly, and then almost in slow motion it fell forwards, Steve and Tony moving quickly to avoid being crushed beneath it. They exchanged confused glances, and then looked around the room, their eyes coming to rest on Natasha, who was once again staring at the hammer in her hand. Clint, too, had his eyes trained on her, having seen what had happened after the creatures attacking him had fallen, and soon enough Wanda and Sam had come round and followed the gaze of everyone's eyes.

"What has happened here?"

They all turned as a deep voice sounded from the doorway, Thor and Jane having returned from their date. They surveyed the damage and the Avengers, before Thor's eyes landed on Mjolnir. He stared at it, before lifting his gaze to meet Natasha's eyes, the shock evident on his face. For a long moment, silence filled the room, no one knowing what to say.

At last, Natasha broke the silence.

"I have no interest in ruling Asgard." She managed, a weak smile curling the corners of her mouth. There was a beat of silence, before one by one the others started to chuckle. Then the laughter grew, filling the room with the sound.

A/N I hope that wasn't too awful, let me know what you think!