AN: I do not own Marvel or any rights to any characters or anything. If I did, I would quit my day job. This is set to take place shortly before AoU. Most of my fanfic is set there, because I love the original six more than anyone else, and I love to write them all together. I typically stay away from ships and focus on friendships instead.

I do reference a few things from the second season of Marvel's Agent Carter, but you don't have to have seen it to follow along.

I suck at thinking of titles, so all of the chapter titles come from the poem Invictus, which is one of my favorites, and the main title comes from the Neitzsche quote about staring into the abyss. Full disclosure: I adore every last Avenger, but Hawkeye is my favorite, so there will probably be a lot written from his perspective. Sorry, Clint, I tend to whump you...

This is rated T mostly for language, but some violence and possible triggers as well.

I hope you enjoy, and that people give me reviews / comments / suggestions. Thanks!

CHAPTER 1: Out of the Night

Clint's body flew back and smashed into a wall, his head snapping back so hard his vision tunneled for a moment. He landed in a crouch with his bo staff held in one hand and a small knife in the other as a roar came from the direction that he had come from. His quiver was long since empty, and he knew neither of the weapons he held would stand up against the opponent he faced. Yet, there was no other choice. With a deep breath, he headed back towards a fight he couldn't possibly win.

Eight hours earlier

"Can you imagine me at Disney Land?" demanded Clint as he flipped a switch above his head.

"Not in a million years," admitted Nat with a small smile on her lips. The two were traveling in a Quinjet, and she took a quick second to admire the sight of the unblemished ocean beneath them. In her earlier life, she had scoffed at those who took time to admire beauty, but she had come to appreciate that life was only enhanced by taking a moment to enjoy yourself.

"So many people," Clint was still going. He said the last word like it was a plague. "I mean, I like people okay, but not, like, up close."

"I know, Clint." Natasha was still amused. "I don't think Laura actually wants to go to Disney. She knows what a nightmare it would be for you. I think she just wants you to start thinking about where you could go on vacation with the kids."

Clint opened his mouth, but she continued before he could jump in. "And not that nasty old cabin. There's nothing for the kids to do. Heck, there's not even running water. You need to go somewhere that Laura can actually relax."

Clint huffed in annoyance. Like usual, his partner had practically read his mind. And like usual, she was probably right. "Well, what do --" he broke off when the comm system chimed.

Nat pulled up the translucent screen and was surprised to see who was calling. "Fury. What's wrong?"

Nick looked even grimmer than usual and didn't bother to dispute the fact that something was wrong. "Romanoff, Barton, I need you to divert to the coordinates I'm sending you."

"Wait, right now? You know we're 8 hours into this flight already? And we just got done being shot at? I mean, a lot?" Clint was not impressed. They were coming back from Beijing and had already been given permission to take a week in San Diego to decompress after a long and difficult mission. Not only had it been physically hard, they had ended up having to kill a lot of people. Despite their job description, that was always hard to recover from.

"I know your situation, Agent Barton." Fury gave him a critical eye. "And I'm well aware of how tired you both must be. But I am also aware of what you are capable of. I also expect you to trust that I wouldn't call you in for something small. This is extraordinarily important."

Clint nodded once, not quite willing to apologize, but acknowledging Fury's words. "Yes, Director. What are we looking at?"

"And what's in Alaska?" added Nat, looking at the coordinates he'd sent. Clint mouthed the word Alaska with dismay, but didn't dare complain again.

"There's a small SHIELD facility there, though it's not manned very often. We use it for research that is especially combustible or for a jump-off point for missions. We sent Stark and Banner there to with a team to investigate some technology we seized recently. Thor went along because, well, he was bored and driving everyone crazy. The second day they were there, their communications became...disjointed. When we requested clarification, their responses became even more nonsensical. Eventually, they stopped responding at all. Rogers took a team to investigate and hasn't checked in since arrival. And now the whole facility is in stealth mode. We can't even see it with our satellites."

"What exactly does stealth mode entail?" asked Natasha cautiously, her brow furrowed.

"It means the whole damn thing moved underground, under the tundra." Fury scowled. Even radio waves can't get out of there. My closest team is 8 hours out. You can be there in two. I need you on this."

"I've already adjusted our direction," admitted Clint. He might grumble, but he'd never leave his teammates hanging.

"What exactly were they studying? And why did it have to be so far in the middle of nowhere?" Natasha asked, eyes narrowed.

"An old employee of Howard Stark's recently died and among his things we found a container holding something he called 'zero matter.' According to his notes, he and Howard both felt zero matter came from beyond our world, and it was far too dangerous to allow do anything but contain it. It sounds like they attempted to get it all off-world – don't ask me the details, I don't understand them – but it looks like this Dr. Wilkes kept a little bit.

"This substance is extraordinarily explosive and dangerous, so we sent Stark out where any mistakes won't kill whole cities. He pulled in Banner because the research notes indicated Howard was considering whether or not gamma radiation could disrupt this stuff and allow us to destroy it."

Clint whistled softly. "Well, shit."

"But there's no evidence of an explosion," mused Natasha. "Does this Wilkes' research talk about zero matter causing illness or confusion?"

"No," Fury scowled again. He had resting scowl face. "But then again, the notes are almost 70 years old. I'll send you what I can. You need to get in and find out exactly what has happened here. I want updates every two hours after you land. From now on, use cover names. We'll refer to the zero matter as uranium ore. Good luck, agents." His image disappeared.

Natasha blew out a gusty breath as she started reading what Fury had sent. "This...is not good, Clint. When will we be there?"

Clint checked his instruments. "Three hours. This is at the ass-end of nowhere. The closest town is Sogwan. Sog-WAN? And that's a tiny town almost 200 miles away. There is nobody and nothing around. We don't have much for supplies, so we'll have to get in and use what's there." He let the silence saturate the air for a while, allowing Nat to read. "What do you think we'll find, Tasha?"

She just shook her head. "I have no idea."