Tony Stark was simultaneously agitated and curious. He'd been woken much earlier than he would have preferred, but it was for a good reason. Or so they insisted. Whatever the case, it was another chance to get an up-close look inside the Shield facility. 

"Remember to keep your hands off things that aren't yours." Natasha reminded him.

"Why does everyone think I'm up to something?" Tony asked.

"You usually are." Natasha retorted.

"Why are we here?" Bruce asked, fidgeting with his hands.

"That's what I wanna know." Clint said.

They fell into silence, not knowing what to do in the meeting room they'd been stuffed into. Tony's gaze examined what he could see through the windows. He watched agents pass by.

"Hey, how young do you guys recruit?" Tony asked after a while.

"No younger than eighteen, usually." Natasha replied, without looking up from her phone.

"So how old are those guys?" Tony asked, gesturing to three agents who were leaning against a wall shoulder to shoulder.

Clint looked up, and his eyes widened. "Oh. That's the Banes."

"The Banes?" Steve asked. "Are they agents?"

"Yeah." Clint said. 

"I thought they were visiting." Steve said.

"Oh, no. If Natasha and I are the top agents, then those guys are legends." Clint said. "They're like walking myths. We know they're agents, and that they are really good at what they do, but we don't know what they do."

"How do you guys not know?" Tony asked.

"Fury likes to have aces up his sleeves." Natasha said.

"Are the Banes related?" Steve asked.

"Siblings." Clint said. 

"I can see the resemblance. But you didn't say how old they are. That one doesn't look like he can be any older than seventeen." Tony said, and Thor nodded behind him, then stopped, not used to the difference between Midgardian and Asgardian age.

"I don't know exactly, but Angel is the youngest. I think he's sixteen." Clint said. "Ash is the middle child, and Achilles is the oldest."

"Achilles?" Tony chuckled. "That's a classic name. Poor guy."

"You know, I don't think that's his birth name." Clint commented.

"Why?" Thor and Bruce asked at the same time.

"Remember I said these guys are legends?" Clint said, "Well, pretty much the only thing we know about Achilles is that you can't hit the guy."

"He's fast?" Steve said.

"He's something." Clint said.

In the pause that followed, they saw Fury walk over to the Bane siblings. As they spoke, the siblings' faces went from neutral to raised eyebrows, to annoyed, and reluctance. Then Fury spun, and walked over to the Avengers.

"Good to see you're all here." Fury said.

"And why is that?" Bruce asked.

"The Avengers are a group of extraordinary people. I know how you work. I also know how they work." Fury tipped his head slightly in a gesture toward the Bane siblings. "But I want to know if you can work together."

"You want to make the team bigger." Natasha said.

"Considering we have to compete with aliens now, I don't think we have any other option."

"He's not wrong. Earth's defenses are lacking." Thor said simply.

Fury glared at Thor for a moment, before addressing the others again. "I want you to play nice, but remember they aren't your friends."

"Don't trust them?" Tony chimed.

"No." Fury said. "The Banes are wild, but I want them on our side."

"Alright. What do you know about them?" Clint asked.

"Not enough." Fury replied. While the Avengers raised their eyebrows and exchanged glances, Fury beckoned the Bane siblings to join them. 

The first to enter was a girl with a spiky pixie cut, black eyeliner, and intense electric blue eyes. She had a small spattering of freckles on her cheeks and across her sharp nose, built like a runner or hiker. She had countless ear piercings, wore a black leather jacket with spikes, and combat boots. She was maybe an inch shorter than Tony.

Next was a boy with wavy hair just long enough to pull into a ponytail, but short enough that his bangs didn't stay tied back, falling to the sides of his face. His eyes were a very dark brown, maybe even black, and he wore all black, save for the fur lining of his jacket. He was pale, with sharp cheekbones and lanky like he'd had a growth spurt, supported by his height which was barely shorter than Steve.

Last was a young man with unruly wind-blown hair the same raven-black color as his brother and sister, eyes a piercing sea-green, and a natural tan complementing chiseled features. The same height as Thor, he was less muscular than the god, but still built. He also wore combat boots and a leather jacket, but without the spikes of his sister's.

Fury addressed them. "If you would introduce yourselves."

"I'm Ash." The girl said, her intense gaze scanning the Avengers, giving Natasha a slight nod of approval.

"Angel." The boy said simply, sounding rather bored. His gaze did linger on Steve for a moment, before he found his jacket cuff more interesting.

"And I'm Achilles." The young man said, imperceptibly wary of Thor. "We know who you all are."

"I'd be concerned if you didn't." Tony said.

There was a long moment of silence. Fury broke it. "I want you to work together. So try to get along."

"Key word, try." Achilles said.

Fury glared at Achilles. "I expect you to."

Achilles looked unimpressed.

Fury turned back to the group as a whole. "Your work will continue as usual, save for more cooperation between everyone here."

"Right. Is that all?" Bruce asked.

"Yes, Dr. Banner. You may go." Fury dismissed.

"Thank you." Bruce said, and slipped out of the room past the Banes.

"I've got a fugitive to track up north, if you don't mind." Ash raised an eyebrow at Fury.

"Go ahead." 

"Dope. See ya, boys." Ash pat her brother's shoulders on her way out.

"Reconnaissance in-" Angel said.

Fury didn't bother to have him finish, and gave a dismissive wave. Angel gave a sharp nod and left.

"Do you have any questions?" Fury asked. "Anything that I should I know?"

A few didn't react, and others gave a slight shake of their head. Thor however, stepped forward. "My Father has asked me to inquire... He thought it would be just to offer that Loki serve here for retribution."

"He wants to know if we'll take Loki and have him work for us as punishment?" Fury asked.

Thor nodded.

"How do we know he won't try to cause trouble?" Fury asked.

"We have power inhibitors. But my Father has suspicions that Loki wasn't acting of his own accord." Thor said.

"He was being manipulated? Controlled?" Natasha asked before Fury could.

"Quite possibly." Thor said. "Loki would have been... Vulnerable."

Fury nodded, thinking.

"Are we really considering this?" Clint asked.

"I'm with Clint." Tony said, looking around.

"I don't know." Steve said. "What if there is more to the story than what we know?"

"Achilles," Fury asked, "What's on your schedule?"

"You're about to fill it with a big headache, aren't you?" Achilles replied.

"That depends. Do you think you can handle Loki?" Fury asked.

"You want me to babysit a god?" Achilles chuckled. "Yeah. I can do that."

The Avengers narrowed their eyes at Achilles.

"Ooh," Tony said, "New guy's cocky."

"If you saw him fight, you would understand where he's coming from." Fury said.

"Speaking of, what can you do?" Clint asked.

"Bake cookies." Achilles replied, deadpan.

Natasha held back a snort. Tony shook his head. "Hey, baking is tricky." Clint said.

"Do you really think you could handle Loki by yourself?" Steve asked.

"You said he'd have a power inhibitor?" Achilles asked Thor.

"Yes. His magical capabilities will be severely restrained." Thor said, not sounding entirely comfortable with it.

"Then I'll be fine." Achilles said.

"So this is really happening?" Clint asked.

"Where are we going to keep him?" Natasha asked.

Fury turned to Tony. "What about your tower?"

Tony thought for a moment, then smirked. "Yeah. That could work."

"Jolly." Achilles said. "Where's this at?"

"New York City." Tony answered.

Achilles tensed. "Of course."

"What, don't like New York?" Tony taunted.

"Don't have the best history." Achilles replied.

"Stark, when could you have the tower ready?" Fury asked.

"By morning." Tony said.

Fury nodded. "Thor, when would our guest be arriving?"

"As soon as you would choose to house him." Thor replied.

~~~

Achilles and the Avengers joined Tony on the trip back to New York, for the sake of convenience. 

"How old are you, kid?" Tony asked.

"Nineteen." Achilles replied. "I'm not a kid."

"Huh." Tony said. "What'd you do to impress Fury?"

"I'm not sure." Achilles said.

Tony looked out the window. "Why do you have a sword?"

"Because I know how to use it." He replied.

It seemed odd to Tony. There were so many other weapons he could use, but he chose to use a sword. The silver hilt caught the light, and looked eerie in a modern sheath.

"What's it made of?"

"I dunno. Some fancy metal mix or something. I can't remember the name." Achilles said.

"You're pretty private, aren't you?"

Achilles shrugged. "You have a lot of questions."

Tony leaned back in his seat. "I like knowing things. Figuring things out."

For the first time, Achilles looked at him fully. It was a long moment, and Tony felt almost uneasy under the gaze of those eyes. Then Achilles looked away.

"What's there to do at your tower?" Achilles asked.

"Lots of tech, video games, that kind of thing. But you'd probably be more interested in the gym, right?"

Achilles nodded. "I don't like tech that much."

Tony looked at him like he'd grown a second head. Then decided he'd better leave that alone or he'd get a headache. 

 "Ash is a bounty-hunter or something, Angel does reconnaissance, right?" Tony asked.

"Something like that." Achilles said.

"Then what do you do?" Tony asked, brow raised.

Achilles looked at Tony. "Well, most of the time, I'm a... Bodyguard."

"Huh." Tony said. "Maybe you and Happy can exchange stories."

"Happy?"

"My old bodyguard, and a great friend."

"Oh." Achilles said. "Maybe."

They fell into quiet, and it was only slightly awkward when the others returned to the main room.

"So, why are you with Shield?" Steve asked.

Achilles leaned back in his seat, and seemed to think over the answer. "Shield found me. And I needed a place to be."

"What made Shield find you?"

Achilles hummed for a moment. And he didn't reply.

"Well, Achilles here said he's a bodyguard." Tony said. "Fury picked you to be Loki's babysitter. Why?"

"Probably because I'm dangerous." Achilles smirked.

The Avengers looked at him cautiously.

"Arrival in fifteen minutes." A voice said over the intercom. 

"Thanks J." Tony replied.

"Oh, that's good." Achilles said under his breath.

"Seriously, kid, what makes you more equipped to handle a god than the rest of us combined?" Tony asked. "We've even faced this guy before, we know how he works."

Achilles looked Tony in the eyes with an intense gaze. "I hope you don't have to find out."

~~~

Two years ago

Fury stood behind a glass divider. On the other side was an unconscious boy. He'd gotten word that the boy was showing signs of waking. As he watched, the boy twitched his fingers, and flinched.

He abruptly sat up, gasping for breath. Then he coughed, crumpling forward onto elbows and knees. Fury saw red splatter on the white sheets. When the coughing subsided, Fury waved away the concerns of the agents, and entered the room.

The boy's eyes snapped up to him. Sea-green, as wild as a storm. The boy pushed himself up so that he was sitting.

"Who are you?" Fury asked.

The boy's eyes narrowed, and Fury saw his muscles tense. "I'm-" The boy began, but he didn't finish. "I'm-" He tried again. "I'm-"

But whatever was supposed to follow 'I'm' just wouldn't form in his mouth, even though Fury saw that the boy knew exactly what he was trying to say.

The boy's hands clenched into fists, and a film covered his eyes as he tried and failed to hold back tears. His breath hitched, sending him into another coughing fit. For a moment, Fury saw panic in the boy's eyes as he struggled to breathe.

Again, the coughing faded, and the red splattering of blood had grown. The boy became incredibly still.

"Who are you?" Fury asked again.

The boy looked at his arms, at the small scars that littered them, collected over the years, and the large one that stood out. Scars, but no injuries.

"Achilles." The boy said, a few tears slipping down his cheeks. "My name is Achilles."