Thank you to everyone who has kept reading, and alerting and favouriting and reviewing this! I'm so sorry for the horrifically long wait, thank you so much for sticking with me!

This has taken forever. I'm so sorry. I shan't bother making excuses though, and just let you read it.

I have also created a tumblr for this story : ] All the chapters are on there, and I'll be able to update on the writing, and I'm hoping write some drabbles and things too : ] the url is samhainschild if you want to go have a look. Feel free to ask me questions on there too, and even ask Loki or Efa if you like! It helps with the character building : ]

Notes:

No Loki or Efa in this one! (Which I think is why it was so hard to write). You get Natasha and Thor instead.

If you have watched the deleted scenes from Thor you'll know that they had their healing stones used by crushing them and then sprinkling them on. I didn't like this, and seeing as it never made the final cut I decided to change them. Instead, my version work by being enchanted by healers or magicians so that their magical healing properties can be used by anyone who knows the rune to release the magic. Once the magic held within the stones is spent they can then be recharged by a healer/magician. Only those with a knowledge of magic can make the stones, but anyone can use them. Personally I think this makes much more sense : ]

o

Chapter Twenty Three:

Frostbite

The base in Alaska was S.H.I.E.L.D.'s most secure facility. Built deep in the mountains, under hundreds of feet of rock and at least seventy-five miles of constantly monitored wilderness from the nearest civilisation, it was supposed to be impenetrable. It was the home of their most secret of operations. Rumour had it that not even the Agents who worked there really knew what was going on in the mass of underground tunnels. So when an alert had rang out that there'd been an unscheduled lockdown there, it was serious business. Code E1 – facility breached by hostile forces.

A response team had quickly been assembled and Natasha, being the highest ranking Agent available, was assigned to lead it. That had been three hours ago, and they'd still been unable to establish any form of communication with the base.

"Coming up now, Black Widow," the pilot informed her.

She nodded curtly, and began readying the thick outerwear needed to protect her from the freezing temperatures.

"Proceed according to plan," she directed, "Bell and Hunt will go with me on recon; Harris, Stone, you'll guard the approach; Taylor, Davies, Wilson, once you've dropped us you proceed to the comms site – see if you can establish contact with any of ours still inside and try and get some more info on what actually went on here. Understood?"

There was an assorted affirmation, which she mostly ignored, concentrating instead on loading her weapons and checking everything was correctly fitted. With distaste she pulled on the thin black gloves. They were a new material, supposed to reduce impact on movement whilst maintaining maximum insulation, but she hated having her hands covered in any way. No amount of techno-fabric could replicate the minute details that her fingers could pick up, nor the precise sensation of the biting point of a trigger. But it was better to suffer this annoyance than risk frostbite.

Five minutes later, she and her team of four agents were being lowered to the location of the entrance to the base with the shortest access route. There were at least five separate entrances in total, some with up to four miles of tunnelling or stairs before they reached the base proper. This one had the shortest access time, but was also the hardest to get into, involving finding and traversing a narrow and precipitous ledge, hidden behind a large outcropping of rock.

Natasha navigated the approach easily but stopped short when she caught site of the entrance, her hand immediately flying to her gun. The cleverly disguised and highly secure door was wide open, the corridor beyond fading into inky blackness where it should have been brightly lit. She grabbed a torch from a pouch on her belt and fixed it into the specially designed slots on the top of her gun, before slowly approaching the entrance. Thick patches of ice covered the walls and floor, and icicles hung from the light fittings above them. Natasha's breath steamed in front of her as she carefully made her way over to the small room to the side of the corridor, where the guards should be stationed. The light of her torch glinted on splintered shards of metal that must have once been the door. Cautiously she let her beam of light fall into the room, revealing the two disfigured corpses that were strewn across the floor, frozen in place.

A second beam of light joined hers and she heard Harris' startled gasp. Natasha straightened up, and turned her torch and her attention to the long corridor. Those men were dead. Nothing could be done about them now.

"You know what you have to do," she told her team sternly, starting down the corridor. After a brief hesitation, two pairs of footsteps followed her.

As they worked their way further into the base, torchlight roaming the walls and floor around them, they found several more of the icy corpses. Every door they passed was either iced shut, or shattered and the absolute silence spoke of the state of the massive generator which should have been humming gently as it powered the base. With each step they took the temperature dropped until even Natasha could feel the cold invading her clothing. It was looking more and more likely that there were no survivors and instinct cried out to her to turn back. But she had her orders, and she would follow them.

The three agents reached an intersection and Natasha silently gave the signal for them to split up, instructing them to keep comm links open. She took the middle of the three paths, the one that led deepest into the mountain. For another five minutes she came across nothing more than ice and corpses. She could feel the cold beginning to seep into her bones, but firmly shoved the sensation aside. She'd grown up through the harsh winters of Russia. Being cold was nothing new.

There was a burst of static from her earpiece, but she could barely make out any words. Those boys at the comms tower better get working fast. Being buried so deep in the rock the only way signal could penetrate this far into the base was through the enhanced relay systems that travelled through the walls, but considering the state of all the other tech, it seemed like they were out of operation too. So she was on her own.

She almost turned back at that thought. This was a recon mission, not recovery or counter-attack. Without backup things could get very messy, very fast if whoever did this was still here. But everything she'd seen so far pointed to the attackers having left and Fury expected answers. She couldn't leave until she had some to give.

There was another burst of static as she turned into a large room, possibly designed for training or testing. Whatever had been there was a mangled wreck now, covered in ice. She swept her torch around it, fingers clenching her gun tight as she ignored the crackling in her ear. If she had been younger she might have turned it off, but she'd learnt the hard way that communications could be re-established at any moment and with vital information. The comm stayed on.

She clenched her jaw to stop her teeth from chattering as she slowly began to pace the room, looking for anything that might tell her what had gone on here. Something had to be wrong. She never felt the cold this badly.

Suddenly she sensed something move behind her and span around, reaching to her hip for her second gun. She froze, scanning the area with her torch beam, but there was nothing there. Her breath froze in front of her face and joined the faint mist that seemed to cling to the floor. Slowly she turned about, searching every inch of the room with her light.

The room was empty. Nothing there but ice. But something had to be there. She was an assassin. She knew when someone was watching her.

There was another crackle in her ear, and it was at that precise moment that she felt a sudden sharp pain across her cheekbone. She spun quickly, eyes desperately searching for whatever had caused her injury, but once again, she could see nothing. Her face almost felt numb where she had been hit, but she could feel the heat of her blood trickling across her skin, almost seeming to burn. The cold was even more intense and it was all she could do to keep her aching limbs from shaking as she slowly rotated on the spot, all senses alert for any sign of movement.

"Na… …n yo… … …e?" Natasha could almost make out words in this burst of static. Hopefully that meant the comms system was almost back up and running.

There was another rushing, invisible attack, but this time she was able to sense it coming and dodge – just about. Blood seeped out of a fresh cut on her left forearm, and a single drop fell to the floor – and froze in midair. Natasha looked down in shock. Surely it couldn't be that cold? Slowly she backed up, still slowly scanning the room as she edged closer to the door. Something wasn't right here. She wasn't trained to deal with the supernatural – at least not alone. And invisible attackers? Yeah, that had to be supernatural.

"Nat…sha …urn t… …ase!"

Okay, so the words were getting clearer. Just a little. She took one more step behind her, eyes still scanning the room when suddenly she felt a piercing cold seeping through the back of her clothes.

She span, bracing her arms and shooting a string of bullets. She still couldn't see anything, but her left arm collided with something, hard. She seemed to have been able to shove it out of the way, but watched in horror as the gun in her hand froze as she tried to pull the trigger.

"Natasha! … re… …o base! …peat! Return …o …se!"

Yep, that was clearer. Return to base. She didn't need telling twice.

She picked up her pace, backing up the way she'd come, still checking all sides for movement of any sort. She'd almost made it to the corridor when something grabbed her injured left arm. A piercing cold suddenly shot through her and a terrible numbness spread across her arm. She struggled, trying to free herself from whatever had her in its grasp, but its hold was too strong. Desperately she shot several bullets into the air before her and around her arm and let out an audible sigh of relief when she felt the grip on her arm slacken. With a wrench she was able to free herself and stumbled backwards before retreating at a full out run. She moved as fast as she dared without slipping, the icy air searing her lungs and the numbness of her arm screaming at her. She didn't dare look back.

When she reached the join in the corridors where she'd left her teammates she paused briefly, wondering if she should find them. But her orders had only been to return. They would have had the same, or… Or they were already dead.

The thought spurred her on. There was less ice here so she was able to move faster. It would be only minutes until she would escape this death trap. She avoided looking at her arm, which she had cradled hard against her stomach as she ran. She knew it was bad. She didn't want to know just how bad until she was safe.

o

It was nearing midnight where the Helicarrier hovered majestically in the cloudy skies above the Atlantic ocean. Thor stood by the large windows of the control room of S.H.I.E.L.D.'s mighty floating fortress, watching as they skimmed the tops off the highest of storm clouds. Above them the night sky glittered and shone in all its glory, and even the writhing mass of dark clouds beneath them looked peaceful from their altitude. The scene unsettled Thor, for he was well aware that all was not calm and good.

His thoughts, and his emotions, were in turmoil. Seeing Loki again had not been easy. The extent to which he had changed saddened him. His missed his brother. Missed the sarcastic remarks that would be whispered into his ear during the tedium of council meetings. Missed the constant banter between them. Missed the way Loki could always tell if he was down and would make him laugh. He even missed the trickery and mischief and chaos that would follow in his wake. To see his brother look at him with such hatred. To have him disown him in such a manner. It cut Thor to his core.

He did not understand what could have happened to change his brother so. The All-Father had told Thor of Loki's true parentage, but, after the first momentary shock, it had not mattered. Nothing could change the centuries they had spent at each others' sides. Their bond as brothers was not in blood, but in their shared experiences, their shared memories. For Thor it would always be so. That it was no longer for Loki worried him endlessly.

The words the red-haired mortal, Efanna, had spoken earlier to him rang through his mind. Not just the description of the pain, the suffering that she claimed Loki had gone though, but the pain in her own eyes as she had spoken. It was impossible to disbelieve words spoken so empathically, and thinking of what that meant unsettled Thor's mind. He knew Loki had been hurt. Something must have happened to make him make claim to Midgard as he had, but the extent to which Efanna had eluded to… He had not considered the full extent of how much Loki might have suffered.

Since Loki had fallen Thor had replayed the last encounters he had had with his brother over and over. Analysed every second, attempting to find anything which might explain Loki's actions, worrying that he should have done something differently that could have prevented all of this. He had been through every memory a thousand times and still it had brought him no insight, nor comfort. He only hoped that these most recent recollections might weigh less heavy on his conscience.

He had done what Efanna had suggested and kept his temper, although at times he had been hard pressed to do so. By controlling his emotions however, he had seen more of Loki than he would usually notice. He could sense the pain behind the venom that laced his words. But Efanna was right. Loki had changed since Thor had last seen him, and that change could only be for the better. Hostility had radiated from him during the months he had been kept in Asgard, even hatred. Whilst much of that had today been again directed at him, Thor had been amazed at the way he had treated Efanna.

He wasn't sure which of the two confused him more in the way they interacted with each other. Efa's confident comfort in his presence was like nothing he had ever seen before. The way she teased him constantly was something few would be brave enough to do, and yet she somehow seemed assured that she would come to no harm. But the way his brother responded to her actions! He had not been angry or violent, had not retaliated in any way. Thor had never imagined that Loki would ever allow someone to undermine his pride as she did. Yet there almost seemed to be amusement in the trickster's eyes when he had looked at her. And the way in which he had caught and held her when she fell…

Thor shook his head and pressed his hand to his eyes. She must be an astonishing creature indeed to wring from Loki such an affable reaction, by his standards at least. And she said she had known him little over a month. The girl was an enigma, and she worried Thor. There was no way she could possess the information that she so obviously did. No way that she should be so comfortable with Loki, and he with her. And according to Stark, no way that she should exist at all, not with a past that could not be traced. It seemed that she was on the side of good – calling them here, giving them information they would otherwise not have had – but what if this was all a ruse? Could she somehow be a conspirator of his brother? They had little but her word to go on that she was telling the truth.

And yet there was an honesty about her that seemed to emanate from her very soul. When she spoke she somehow seemed to infuse her words with such emotion that made her impossible to believe false. And the words that she had spoken had shamed even him. Surely none, not even his brother, could lie with such complete conviction as that? Moreover it was obvious that there was something amiss in Midgard, and everything that she had told them seemed to tally up with what they could discover of this strange phenomenon. It was as the Doctor Banner had said, they would just have to wait for her explanation.

The sound of footsteps interrupted Thor's thoughts and he span, warily, still not comfortable in this flying fortress. He relaxed when he saw they merely belonged to the archer, Barton.

"Can't sleep?" the agent asked, coming to stand next to Thor, and watch the clouds.

"I am not tired," he replied, "Time flows differently between the realms. Were I still on Asgard it would not yet be late. It will take some time, I think, to adjust to the difference. Besides, I wish to be ready for when Natasha returns. The girl, Efanna's, words worry me."

"Yeah, me too."

The man's words were short, his voice tight. Thor turned to look at him, assessing his stance, the way his brow furrowed.

"You care for her a great deal, don't you?" he asked.

Clint grunted slightly, his eyes staring straight ahead.

"We have history. She was there when I needed her. I'm gonna be there when she needs me."

"It is good to have such companions," Thor agreed, delicately letting the subject drop. He was not quite so oblivious as some thought him.

"She is a skilled warrior, I am proud to be able to say that I have fought by her side."

Once again, Clint merely grunted his response.

"The girl, she said that Tasha's injuries were 'beyond Midgardian medicine'," the agent muttered after a moment, "Will you be able to heal them?"

He turned his head to look up at Thor, and the Asgardian could see the desperation in the man's eyes.

"I do not know until I have seen the wound," he replied sombrely, "I am no healer, but every warrior of Asgard has in his possession a number of healing stones. They are usually sufficient for all but the most serious of injuries. I can only hope that it is so in this case."

Clint grunted again, turning his eyes back to the window. They stood in silence for a few minutes, each man consumed by his own worries until their thoughts were interrupted by the somewhat timid voice of one of the agents working the night shift.

"Uh, excuse me, Thor? Agent Romanoff's jet has arrived. You're wanted in the medical bay."

The two men were moving even before the agent had finished speaking.

"I'll show you the way," Clint barked, shouldering past the woman. Thor followed, matching the archers pace easily.

The route Clint took them was not a simple one, but was relatively short; within a few minutes they had arrived in the main area of the medical bay. The agent working on the front desk took one look at them and directed them to a room two doors down the first corridor. Natasha was sat on a chair, wrapped in blankets, whilst one of the medical staff slowly unwound the loose bandages that covered her left arm. She looked up as they entered, one eyebrow raising slightly. There was a gash on one side of her face, around which the skin was a purplish colour.

"This really is serious then?" she asked, turning her head to the corner where the Director stood.

"Apparently about as serious as it gets," Fury answered, his gaze turning to Thor, to whom he gave a slight nod.

The Asgardian could sense the reluctance with which he spoke, and suspected that he did not wish their conversation to be overheard by the healer. He returned the nod and moved to Natasha's side, watching intently as the bandages were removed. The skin beneath was blackened and blistered. It was not a pretty sight, even the healer was looking somewhat shocked.

"Frostbite?" Thor questioned.

"It would appear so," the woman answered, looking timidly up at the agents and the Director, "I'm not sure how much I can do…"

Barton moved to stand behind Natasha, his face grim as he placed a hand on her shoulder. Natasha's own face betrayed no emotion.

"It will need to be re-warmed before I can use the stones," Thor instructed.

The woman nodded as she finished removing the bandages around Natasha's arm, then gently moved it to a small water bath.

"This is set to around one-hundred-and-five degrees Fahrenheit," she explained, "You'll need to keep an eye on her heartbeat and core temperature, make sure she stays warm."

She looked around questioningly, her eyes lingering on Fury.

"Is there anything else you want me to do, Sir?" she asked.

The Director's eye jumped to Thor, his eyebrow raising slightly.

"You have done all that is required," he assured her, "Thank you for your assistance."

The woman's eyes shifted back to Natasha, and then back to Fury again, before she reluctantly went to the door.

"Ensure the water remains at the right temperature," she instructed, before she left, "And call me if pain meds are required. The re-warming process is painful."

The Director checked the door was properly closed once she'd gone, and then moved to take a seat opposite Natasha.

"I think it's safe to say the mission didn't exactly go to plan," he stated.

"It seems things aren't going quite so smoothly here for you to insist I give my report in person," Natasha retorted, raising an eyebrow.

"There have been certain… complications," Fury admitted, "But first, I wanna know what happened in Alaska."

Natasha nodded, and looked briefly down at her arm.

"It's a mess," she reported, "Facility was wide open, completely destroyed. All tech was down. No survivors. I sent Taylor, Davies and Wilson to work on comms; Harris and Stone were stationed to guard the approach; Bell, Hunt and I were on recon – I was the only one who came back."

She paused for a moment, her eyes distant. Thor noticed Clint give her shoulder a quick squeeze.

"There was no recognisable sign of the attackers. Nothing to give any clue on ID, or at least, nothing I could explain. But the whole place was frozen – literally – and the deeper in I went, the colder it got. It wasn't just ice though, there were doors that had been … shattered somehow, and the bodies… If you think my arm's bad, you oughta have a look at them. And there was something there…"

"What sort of 'something'?" Fury interrupted.

"I dunno. I couldn't see it. Whatever it was, it wasn't natural and it was hostile. It attacked – two projectile hits, and then it grabbed my arm as I was attempting retreat. Bullets seemed to do something, I can't really say – but they seemed to make it let go. It froze my gun on impact and, well, you can see what it did to my arm. No visual throughout the entire thing."

The group were silent for a moment.

"That sounds like the creatures Efanna described," he noted. Thor was worried. From what he knew, there should not be such creatures on Midgard.

"There's been another encounter?" Natasha asked, sounding surprised.

Fury nodded.

"At 8:20 this morning, Stark received a phone call on a secure line. The girl who'd called him then proceeded to tell him that she had information on the current abnormal weather, but that she would die if he didn't come to collect her immediately. When he arrived they were attacked by invisible creatures that used ice as a weapon which only she claimed to be able to see. She is also the one who first alerted us to the danger you were in, and the one who prompted the order to get you out. She knows an astounding amount of classified information, but is refusing to tell us how until 'everyone's here' – which means we've been waiting on you. Stark did a full background check on her and found nothing. He says that, as far as he can tell, she doesn't exist. Stark may be an arrogant pain the ass, but if he can't find anything on her, then sure as hell, nobody else is gonna."

Natasha's brow furrowed at the news

"Where is she now?"

"On board, asleep. She's under guard and surveillance. I've agreed to wait until morning for her to spill the beans. She's been cooperative so far."

Fury and Barton shared a look, and Thor knew what was coming next.

"There's one more thing you should be aware of," the Director started, "She had Loki with her."

"Loki?"

Natasha looked shocked. Thor supposed it wasn't really that surprising, none of them had known he had been sent to Midgard.

"Loki was stripped of his powers, bound in mortal form and banished as punishment for his crimes," Thor explained, "The girl, Efanna, somehow found him, and took him in."

Natasha raised one eyebrow delicately.

"Some kid just happened across Loki and decided to take him home?" Her tone was incredulous.

"Yeah, that was more or less my reaction," Clint muttered from behind her.

"We should not judge her harshly," Thor insisted, "She has done nothing wrong, and I believe her actions may have helped this situation far more than anything else could have."

He felt strangely protective of the young redhead. She had been the first person since the 'incident' to look at Loki as a person, and seemed capable of provoking a side of him Thor had long feared might be lost forever. For that he would always owe her a debt of gratitude. Perhaps she could even help him further, as she claimed she might.

"We don't know that yet," Barton argued, "She still hasn't told us where she got her information. She could be working with Loki against us for all we know."

"I do not believe that to be true," Thor maintained.

"Whatever she is, we'll find out tomorrow," Fury remonstrated with a stern glare, "She is not our main concern right now."

He looked pointedly towards Natasha's arm. Thor nodded and bent down to inspect the frostbitten flesh, still submerged in the water bath.

"How does it feel?" he asked.

"I've had worse," she replied with a grimace, "Not by much, but I have."

Thor gave her a small smile. The woman was certainly brave. Slowly he reached into the water and gently felt her blackened skin. It seemed to yield to his touch, he thought it was probably ready. Inwardly he wished Loki was here. His brother knew far more about the healing arts, whereas Thor was working mostly on guesswork and instinct. But it was all he could do in the situation. Loki would not help, and he did not have his magic even if that were not the case.

"Remove your arm, and gently dry it – do not rub the skin, that will only make it worse," he instructed.

Natasha did as he asked whilst he dug in his pockets for his supply of healing stones. He chose a fairly large one and held it just above Natasha's injured arm, the others watching him intently.

"Keep it still," he directed before clearly enunciating the name of the rune carved upon the stone's smooth surface and fixing his mind upon the frostbitten flesh.

The rune began to glow softly, and the same glow encased Natasha's arm in a golden light which lingered for perhaps a minute before slowly dissipating. When it cleared her arm was revealed, the skin once again pale and unblemished.

So, what did you think? I hope it's okay, especially after so long a wait! I felt we needed more of the other character's reflections on Efa and Loki, and that the threat needed building up a bit. Let me know.

Love you all x