Wow, guys! It sure has been a while. Not as long as some of the breaks I've had in the past, but still... I'm sorry to have kept you waiting with (hopefully) at least somewhat bated breath. But, here's the new chapter! Yay! I'll try to be quicker about the next one. :-)

Also: bonus points to the people who catch the Serenity reference!

Early in the morning, before anyone was stirring in the villages, a grey stallion rustled through the forest like a ghost. His rider spent more time scanning the trees than he did, squeezing him onward resolutely even though he had traveled this route many times before and knew every turn.

When his hooves finally clattered against the remains of the Rainbow Bridge, he snorted. His rider usually let him canter this bit.

At the smallest nudge of a spur, he lept into gait, tucking his head and pushing off with his powerful hind legs. The bridge didn't offer much traction, but he was accustomed to its slick texture; enough rides down its length had taught him to mind his footing.

When he neared the edge, he slowed to a trot and then walked a stride before halting, streams of fog huffing from his nostrils. He shook his head as his rider dismounted, loosening the reins so that they hung in low loops by his neck. He knew she would be a while.

The rider strode down the remaining part of the bridge to where Heimdall stood, sword in hand, staring off into the vast expanse of space. She didn't bother announcing herself, for he already knew of her presence. He had likely foreseen her coming.

"I was told to come and speak with you at once," she informed the Gatekeeper.

"Indeed," Heimdall replied. He didn't move, not even granting her a turn of the head. He was like a statue, save for speech.

Sif stood for a long moment, attempting patience and waiting for her brother to explain himself. He never did, so she prompted him: "What did you wish me to know?"

Heimdall waited a few seconds longer before speaking, and Sif wondered if it might have simply been to annoy her. "A portal to Midgard is opening," he finally said.

Now it was Sif's turn to stand speechless, struck dumb by the news. When her voice returned to her, she choked, "With your consent?"

"I am afraid not."

"Whose then?"

He hesitated. "You will not like the answer."

"Heimdall!" Sif exclaimed. "This is important!"

"Believe me, sister, I am aware." He looked out over the cosmos again, taking a breath before answering her. "The Chitauri," he said.

Sif swore. "Again?"

"Unfortunately."

"Why?"

Heimdall's grip on his sword tightened reflexively as he said, "My understanding is that there is something of value on Midgard, and they want it."

"But they never work of their own volition." Sif was pacing now, striding evenly back and forth across the width of the bridge, agitated as a penned lion.

"That has been the case in the past, yes."

"And now?"

Heimdall paused; the wait was agonizing for Sif. "I cannot be certain," he told her, "but I get the sense that the tradition has been broken."

Again, Sif swore. Then, hissing out a breath, she rounded on her brother. "What could Midgard possibly have? The Chitauri do not see value in anything!"

"Not as you and I see it, no."

"The only value they recognize is the value of a victory," she snapped. "And they lost on Midgard. They've got no spoils to claim. Besides, the Chitauri rarely take interest in Midgard anyway. Why are they suddenly risking their forces for a realm that they deem worthless? It makes no sense."

Heimdall offered no response.

"If the Chitauri are using all that energy to conjure a portal, then Midgard must be important to them somehow." She kept pacing, her hands bunched into fists that swung angrily at her sides. "It has something they want, but what? Think!" she commanded herself. "If not to cash in on a victory, then why are they there?"

"Sister."

The sound of Heimdall's voice made her stop and look sharply at him. "What?" she shot.

He waited just a moment for her ire to calm, and then he told her, "While the Chitauri work at opening the portal, the fabric of the universe is weakened. With it in such a state, there is a chance that I can give you just the answers you desire."

"Then do it," she demanded. "There is no time for games."

"It is not that simple," he returned. "I cannot just tell you what you wish to know. But I can offer you something much better." Heimdall turned back to the splintered edge of the Bifrost, raising his sword. At first, nothing happened. Then, the cosmos slowly began to converge on his blade, gradually increasing in speed, spinning like a whirlpool. In a blinding flash of light, a new portal ripped into existence just beyond the remains of the Bridge.

Sif stared in wonder, watching the milky nebulae shift and turn within the portal, showing nothing at all but offering her the world. "Why did you not do this before?" she breathed.

"There was not enough residual energy from the Chitauri until today," he said. "This is why I summoned you here. You now have an opportunity to travel to Midgard and assist Prince Thor in his quest for its protection. It is more than possible that Midgard also may hold the answers that you seek."

Taking a tentative step toward the portal, she extended an arm, immersing her hand in it. It felt cool – the pleasant sort of chill that made her nose cold while the rest of her stayed warm. The same chill that had surprised her the first time Loki had touched her hand, making her pull away. The same chill that had thrilled her with every touch since.

She withdrew her hand again, looking at her half-brother. "I just . . . jump?"

He nodded.

"And then?"

Heimdall took a breath. "Travel via portal can be unpleasant if approached incorrectly. Do your best to stay still, and let the portal carry you like you're a leaf on the wind. Keep your mind focused on your destination at all times – be it a place, a person, or a time."

Sif puffed out a short sigh. "Alright," she said, a nervous tongue darting out to wet her lips, "I'm ready."

"Then jump,"

She backed up a few steps, focused on the portal that hovered out in the middle of space. If she missed – she hated to think of how long a fall that would be. "Just think of where I wish to go?" she clarified.

Heimdall gave her a bland stare. "The portal will not stay open forever."

"Alright," she said again. Then, she took a deep breath and hurtled herself forward, pitching herself off the end of the Bifrost.

For an instant, all the blackness of the universe yawned from beneath her.

For an instant, she knew the sheer terror that Loki had felt moments before his fall.

Suddenly, a uniform pressure closed in around her, as if she had just slid into a slender tube. Instinct told her to wriggle, but Heimdall's instructions to stay still overpowered that notion immediately, and she straightened herself out.

The tube was cool around her, just like it had been when her hand was the only thing engulfed within the portal.

She thought Thor's name with all her might, even saying it aloud in case the portal needed proof that she wished to be taken to him; as she rocketed off into nothingness, she clenched her eyes shut.

Thor.

Thor.

Thor.

But the face that hovered beneath her eyelids was too pale to be Thor's. The hair was too dark, and the skin was definitely too cool.

Thor looked back at Steve, who gripped his shield apprehensively. The soldier met his eyes, the glance thick with conversation despite the silence.

"How long?" Bruce asked over the comm.

"Until they strike at us," Elizabeth answered. "We cannot be the ones to initiate."

"Right," Tony returned. "So we let them pummel us into the concrete, but the moral high ground is ours."

Thor jerked at the weight of a hand on his shoulder. "Oh," he said. "Only you."

Elizabeth didn't smile. She didn't smirk. She only asked, "Are you ready for this?"

With a sigh, Thor replied, "Is there a choice?"

"None whatsoever, it appears."

For the first time, Thor noticed her lack of armor.

She must have seen the concern in his eyes, because she shook her head. "I'll be fine," she murmured.

"Forgive me if I don't believe you."

Elizabeth looked at him somberly for a moment. "You used to," she said.

"We have both changed since then," Thor told her gently.

"Sometimes," she mused, "I wonder if we will ever stop."

He frowned in confusion, but she only walked away, taking her position at his right flank – the station which he had insisted belonged to her. He had also requested that Steve be on his left; something about his shield reminded Thor of the many battles that he had fought for the glory of Asgard. He himself never used a shield, but Sif, his left flank from home, liked to keep hers close.

He gripped Mjolnir tightly as a bright glint from one of Elizabeth's knives flashed in the corner of his eye. It was such a familiar sensation – he almost wanted her to throw it right then, just so that he could watch her do it. Before the fighting started, and they both would become too busy to take any notice of each other.

She was staring at the growing portal, stoic and resolute. Her lithe fingers twirled a dagger, feeding it through them and flicking it up, catching it by the flat of the blade, and doing it all over again. It was an absent-minded routine – deft and practiced.

All around them, inside any building with windows, civilians peered out at the group that they hailed as heroes. Thankfully, there had been little protest when Tony, Steve, and Bruce had gone out an hour earlier, telling the public to hide – anywhere with four walls and a ceiling. The word of an impending attack had spread like wildfire down the New York street, and the people – still sensitive enough from the last attack to understand – had gradually disappeared. Initially, they had all avoided windows as Tony had instructed; but it had been long enough now for them to grow bold, watching the Avengers with bated breath.

Something was about to happen; they could all sense it in the air.

Elizabeth felt as though her whole body was tingling with electricity. Tension was high, and she was ready for whatever from the sphincter of hell descended from that portal.

Or so she told herself.

The cold metal of the knife had grown warm after all her playing, so she tucked it back into her belt, grabbing another. Feeling the cold on her fingers helped keep her mind in the here-and-now.

Crack!

She barely had time to turn toward the ear-splitting sound before something – or rather, someone – landed squarely on top of her, knocking her to the pavement.

Her knife clattered out of her hand, but she was powerless to go after it. In fact, she couldn't even turn over to see where it went.

Limbs were everywhere, flailing as the two bodies struggled to separate, and, somewhere along the way, Elizabeth's nose got jammed by an elbow that she was certain was not her own.

"Just stop moving!" she yelled in frustration, already feeling blood on her face.

The other party did no such thing. "Sorry!" exclaimed a female voice. "Sorry! I'm trying to –"

With an annoyed groan, Elizabeth pushed the other woman off of her, sitting up and dabbing at her bloody nose with one hand while pushing her hair back with the other.

"Who are you?" the woman asked.

Elizabeth looked at her. Instantly, recognition dawned. "Sif," she breathed.

The warrior woman knit her brow, staring suspiciously at Elizabeth. "Who are you?" she repeated, this time with more acidity.

Elizabeth blinked. She shook her head a little. "You would not believe me if I told you."

"Try me."

"Sif!" Thor took her hand and hauled her to her feet, embracing her fondly. "My friend," he said.

"Hello, Thor," she replied, smiling tightly. "I heard you have a problem with a portal."

Slowly, Elizabeth got to her feet. Her head was pounding, and she attributed most of the pain to the fall; the rest, she attributed to the one who had fallen on her.

"This is Elizabeth," Thor told Sif.

Sif nodded courteously – if a trifle confusedly – at Elizabeth. "I apologize for landing on you," she said. "I have never traveled by portal before."

"Heimdall opened a portal?" Thor asked.

Sif looked back at him. "There was just enough energy to do it, but yes."

"Thor?" Tony asked over the com. "What just happened?"

While Thor explained, Elizabeth stared at Sif. Her eyes darted down and found the warrior's right wrist. A black band of leather wrapped twice around it, secured with an elaborate knot. "Where did you get that?" she asked.

Sif turned to Elizabeth, following her gaze to the leather bracelet. "That is none of your concern," she responded, wrapping her other hand around the cord protectively.

Elizabeth shrugged, nonchalantly guiding her skewed hair back into place. "I was merely curious."

"Don't be."

"Did Thor give it to you?"

At that, Sif's face contorted just a bit – enough for Elizabeth to notice. "No." There was enough ice in that word to convince Elizabeth to stop there and proceed down a new vein of questions.

"What are you doing here?" she asked, brushing off any lingering concrete dust and straightening her knife belt.

"I came to help defend Midgard from the Chitauri scourge." Sif pulled her staff from her back, giving it a twist and extending the blades.

"How noble of you," Elizabeth drawled, reclaiming the knife that she had dropped when Sif had landed on her. She toyed with it for a moment, looping it in and out of her fingers, flipping it over the backs of her hands, tossing it around like it was as harmless as a twig.

Sif was watching her. Elizabeth could feel her eyes on her with every move she made.

"I hope you are prepared to use that in battle and not just for silly tricks," Sif stated dryly, indicating Elizabeth's knife.

Elizabeth caught it smoothly, spinning it in her palm so that she was gripping the handle. "There's no need for such curtness," she said. "We are, after all, here in common cause."

Sif was quiet for a second. A muscle in her jaw flexed, and she sighed. "You're right," she conceded. "And, if we are to fight together, we should at least behave as comrades."

Elizabeth just looked at her expectantly. When Sif said nothing, she hinted, "Whenever you're ready to start, then."

"Forgive me."

"Of course," Elizabeth replied, politely dipping her head. "See? Not that difficult."

Sif scoffed and then, with a somewhat pensive stare at Elizabeth, she noted, "You remind me of someone."

Elizabeth arched a brow, saying, "I can assure you we've never met."

"No, of course not." Sif said, brushing it off like it was nothing. But she still stole one last glance at Elizabeth's face before muttering, "Of course not. Excuse me," and heading to Thor's side.

Elizabeth went back to watching the portal and playing with her knife; the mass of swirling clouds somehow didn't hold her interest as it had before, though. Now, all she could see was Sif, lining up behind Thor, brandishing her weapon expertly, ready to offer the coming battle every bit of life within her.

A sharp pain pulled her attention back, and she held up her left hand, inspecting it. Blood dripped down her wrist from a sizable but shallow gash that had just been torn open across her palm. Her knife laid on the ground, glistening red at the edge.

"First casualty: Elizabeth's hand," Steve so graciously announced to all on the comms.

Now Sif was really watching her.

She coughed out a short, tense laugh, shrugging it off. "Funny," she said. "Very funny."

"Come on, Elizabeth, stop showing off," Clint scolded her, his sarcasm lifting the mood just a bit.

"And here I thought trying to impress the girls was my thing," Tony added.

Elizabeth was about to reply when Bruce cut over them all. "Uh, guys? I hate to ruin the fun, but am I the only one seeing this?"

Silence fell as everyone turned to the portal.

The Chitauri had begun to descend.

"Alright," Natasha said. "Let's save the world."