Disclaimer: Oh you know, the usual. Not mine. I make no money. All characters belong to their respective owners.

Author's Note: The first part of this story starts a couple years before the movie and goes to just before the movie starts, then the second part picks up at the very end of the movie and goes to only a few weeks/months after the end. There'll be more Sigyn and Loki stories after this one. :)

I

"I think you have an admirer, Loki," Thor said, glancing to a group of girls on the other side of the great hall. "She keeps looking at you."

The girl in question was Sigyn. The last lady Thor had danced with had informed him of her…admiration for his brother; and now that she had mentioned it he saw it, too. She was alone, her back against the wall, and every so often Thor would catch her glancing at his brother with a shy smile before turning looking away, always tucking a piece of long light brown hair behind her ear.

Thor hoped that Loki would look over just as Sigyn did so that he might see her, but he was a moment too late.

"I'm sure she was looking at you, brother, not me. You should ask her to dance."

"I've already promised several other ladies a dance tonight. And I think Sigyn would be much happier if you asked her."

"I doubt that." Loki watched Sigyn for a long moment, his face a carefully neutral mask. "You're certain she was looking at me and not you?" Thor heard a faint trace of hope in his brother's voice.

"I'm sure of it."

Thor lost track of his brother as the night went on until Sif, who had apparently heard this rumor as well, nudged him and pointed across the room.

"Looks like Sigyn will get her dance."

Even from the other side of the hall, Thor saw her face light up when Loki offered to dance with her. And judging by the rare, genuine smile that slowly crept onto Loki's face, he guessed there would be new rumors going around the palace.

II.

Sigyn and Loki guarded their privacy jealously, sneaking away at odd hours to see each other. Thor rarely saw them together, but whenever he returned Loki looked as though he was barely able to keep from grinning.

One morning his curiosity got the better of him, and Thor and the others followed them to one of the gardens, where they sat beneath a great tree covered in knots and bumps. Loki's books and scrolls were spread out on a blanket before them.

"Seems you were right about them,"Volstagg said.

"Told you."

Sif rolled her eyes. "It's impolite to spy on them." Hogun nodded in agreement.

"And yet here you are, spying right along with us," Thor reminded her.

She shifted almost uncomfortably. "I'm not spying. I'm only making sure you four don't do anything foolish."

"Right."

"Is he…teaching her magic?" Fandral asked. Loki guided her fingers in what Thor assumed were the proper movements for some spell. Something dark coiled around her wrist and she let out a small gasp. "He showed her the snake trick?"

Most girls were frightened or disgusted by Loki's tricks but Sigyn was neither. Instead she ran her fingers over the snake and giggled. Loki leaned in and whispered something in Sigyn's ear, and Thor felt an immediate twinge of guilt for peeping on such an intimate moment between the two of them. "We should go."

Something slithered across the back of his neck and up into his hair, something that tingled with magic. Thor jumped back, batting at his hair, and as he did so tumbled into Sif and Volstagg. A small green snake, no longer than the length of his hand, fell onto the grass before fading away.

"Hello, Thor!" Sigyn called, waving at him.

Thor dusted himself off as best he could. "I see my brother has been teaching you to cause mischief as well as magic."

"That's because she has such a talent for both. Wouldn't you agree?" Loki said as he slipped an arm around her waist.

"She has learned from the best." With nothing wounded other than his pride, and even that not terribly so, Thor led his friends away, Loki and Sigyn's laughter echoing behind them.

III.

Thor always woke before dawn to start training. Occasionally, Sif or Hogun or sometimes Volstagg would join him. Fandral and Loki insisted on waiting for the sun to rise before they did.

This morning he was alone, with Mjolnir's weight at his side as he made his way to the training rooms. The halls were still cast in shadows that seemed to shift as dawn approached. But it was the quiet he craved now, the calm he needed just days before his coronation.

Out of the corner of his eye Thor thought he saw something in the shadows. Then a brief ruffling of clothes. The faint footsteps that came to a halt when he did. Instinct guided his hand to Mjolnir. "Who's there?" His voice was quiet, like the soft rolling thunder of a distant storm. "Show yourself."

"It's only me, Thor." Loki's voice came out of the shadows first, followed by his physical form. His hands were up in defeat. "No need to destroy the hallway."

Thor let out a massive sigh of relief. "You know you shouldn't sneak up on me like that."

"I wasn't trying to."

Now that Loki had shown himself, Thor noticed something was off. "Are you…wearing the same clothes from yesterday?"

"Yes. I fell asleep in the archives." It certainly was plausible. It wouldn't be the first time Loki was too caught up in his reading and nodded off with book still in hand.

There was something familiar, though in his brother's appearance. His day old clothes smelled vaguely of perfume, not dust from the archives, and his hair was messy, which it never was. And Loki probably thought he was being discreet, absently tugging his shirt closer to his throat, but Thor could still see the faint bruise just under his collar.

Once in a while, Thor liked to think that Loki wasn't the only clever son in the house of Odin.

"Well then. I hope what you were, erm, studying, was considered honorable for a prince of Asgard," he teased.

"I hardly think you're one to lecture me on honorable study habits, Thor."

But it was the way Loki smiled, partially hidden by the shadows, that told him his suspicions had been right.

IV.

That Sigyn was devoted to Loki was beyond question. Even when they were younger, she would take Loki's side in an argument, and later she would be part of whatever mischief he had planned. So Thor really shouldn't have been surprised by Sigyn's latest show of loyalty.

She arrived early at the feast, just after he did. Dressed all in green and black and gold accents, she was a haunting echo of his brother. And where everyone was joyful, Sigyn was aloof and guarded. The only thing missing from her imitation of Loki was the helmet.

It was painful to watch her. Save for his mother, no one else even regarded her presence. Effectively shunned by everyone at the feast, Sigyn kept to the outer edges. It infuriated him to see her treated that way. Whatever his brother had done, she did not deserve to be ostracized for her devotion, when she had most likely been ignorant of his brother's plans same as everyone else. Thor moved toward her, to support her and hopefully convince everyone to treat her better. But as soon as he got too close, she was gone, slipped to the opposite end of the hall as him. Once more he tried to cross to her, and again she moved, until it was clear she was avoiding him.

Thor decided it would be best to let her be for a while. Sigyn remained by one of the pillars, watching. Every cheerful boast and joke chipped away at the impassive front she had put up, until there were unshed tears in her eyes and she regarded the room at large with equal parts anguish and disgust. When she brought her hand to her mouth to suppress a sob, Thor couldn't leave her alone. He moved quickly through the crowd before she had a chance to run.

"Sigyn, I-" He reached out to her but she batted his hand away lightly. Her eyes locked with his and in that moment felt and shared the full extent of her pain.

"Do not speak to me, Thor." Her words cracked like a whip. "You let him fall."

Someone called to him, and when Thor turned back towards her, Sigyn had disappeared into the shadows.

V.

Sigyn remained on the fractured end of the Bifrost late into the night. Thor waited for her, discreetly of course, until a guard told him she had left the bridge and had gone back into the palace.

He followed her at a distance, even when she didn't turn down the corridor to her rooms, but rather towards where Loki's rooms were. He waited until after she had slipped into his brother's room, the door not closing completely behind her, before peeking in. Sigyn was sitting on the bed, her back to him, Loki's cape pressed to her face to muffle her sobs. His heart anew broke with each one.

"Sigyn." She froze mid sob, and Thor was certain she'd vanish again.

But instead she pulled the cape away from her face with trembling hands, and she tried to regain some of her composure. "I shouldn't have said that to you, Thor. It's not…it's not your fault."

"Sigyn, I am so sorry for what happened," he said quietly as he sat next to her.

"As am I." Whatever calm Sigyn had found was slipping fast. Her gaze was fixed on the ground and her lip trembled. The green fabric of Loki's cape twisted in her hands as she gripped it tighter. "Loki is dead and everyone is celebrating." He voice cracked on that last word, tears streaming down her face as her resolve shattered. "You saw how the feast was. Volstagg was stuffing his face and Fandral had a new group of women on his arm, and…and no one but you and I even cared that he's gone!" She wiped at her nose with her sleeve. "How can you stand it, Thor? How can you stand to sit by while your friends drink to your brother's death?"

"They drink to Asgard's safety, nothing more." He was too weary to fight with her, to explain to her the political reasons behind the feast. Nor did he think she would care even if he did, because he hadn't cared when his father explained it to him. His return to Asgard had saved it from the danger Loki had put it in, and his father wished the whole realm to know that.

"Safety that was bought and paid for with Loki's life!" She yelled, and then her anger was gone as quickly as it came. "And I cannot bring myself to think the price was worth it."

If there had been any way for Thor to have kept Loki from letting go, if he could have kept the whole fight from going the way it had he would have done so without hesitation. There was a tightness in his throat and tears stung his eyes as Thor placed an arm around her shoulders. At first she went rigid at his touch, but soon collapsed into another wave of sobs that he held her through, even as his own threatened to escape.

"Sister." He supposed he could still call her that. They may not have been married yet, but both he and his parents had believed it was only a matter of time before they would have been. "I miss him, too. Every day. And more than anything, I wish things had ended differently. But I know my brother would not want you to suffer like this over him. And I promise, I will do everything in my power to make sure that his memory is honored. For you." For the both of us.

Her voice was a small, hollow, broken thing, and Sigyn could barely look up at him. "Thank you…brother."

VI.

In the days and weeks following his return, Thor watched as Sigyn's behavior drew the attention of the gossips at court. Most of her time was spent on the Bifrost, where she would stare over the edge for hours. She gave no reason for it when asked, saying only she would continue to do so until construction of the new observatory began. She'd been seen coming out of Loki's rooms as well, or sneaking off to the archives at odd hours. Despite his efforts, rumors of her involvement in Loki's plans continued to crop up like weeds, and Thor could only hope Sigyn never heard the worst of them.

Thor spoke to her only once after their last conversation. Sigyn had taken to practicing her magic in her and Loki's favorite garden, away from the prying eyes and ears of court. She was still guarded but seemed to be in a better mood, and they talked of happier times, of Loki and all the mischief and adventures they got into when they were younger. It helped him heal to see her like this, with some measure of peace.

When his father asked to see her, despite his and his mother's protests, Thor's heart sank. To be brought before the All-Father and questioned, even gently, he feared would break her and any progress she made. But his father had commanded it, and Thor went to find her after her daily trip from the Bifrost.

When the guard told him that Sigyn hadn't come to the Bifrost at all that day, Thor checked both her rooms and Loki's. They were empty and immaculate, as though they had not been inhabited for years. There was no sign of her in the gardens or the archives either. Her family, the guards, cooks, servants, all claimed not to have seen the lady Sigyn since the previous morning. Heimdall was a last resort only after Thor had nearly torn the palace apart looking for her. But when asked, the gatekeeper looked puzzled.

"Strange. I can neither see nor hear her, just as it was with Loki and the frost giants."

In the end, and after much debate, it was decided that there were to be no search parties sent out for her, and that she would be dealt with should she return. He wasn't sure what was worse: for her to stay missing or for her to come back. As Thor watched as night fell upon Asgard, he asked his mother if she thought Sigyn was alright and why she would run.

Frigga was silent for a long, thoughtful moment. "She is clever and resourceful, as your brother had been. I do not think she would have chosen her own exile if she didn't believe it was necessary. As for if she's safe," she placed a reassuring hand on his shoulder. "The Bifrost is still broken. She will not be able to leave Asgard, and as long as she's here, no harm will come to her."

Thor hoped she was right.