A/N: Right. So I saw a thing on Tumblr and this popped into my head and wouldn't go away until I wrote it. It was supposed to be a one shot but it's turning out to be a lot longer. I also don't know where I'm really going with this. So, yeah. I don't know when I'll be updating this. Hopefully it won't take too long. This is un-beta'd, all mistakes are mine. Title from a Led Zeppelin song(it may change).

"I'm sorry."

When Barton joins them, he isn't alone. He brought along Doctor Foster's intern, Darcy. Steve and James share a look. They're both carrying guns but Clint also has his bow and arrows. Darcy has a baseball bat with nails sticking out all over the top like a homemade mace. She has little vials attached to her belt, too. They clink together whenever she moves. Barton has on his uniform and Darcy has on some cargo pants and long sleeved shirt on. She's sporting a blank face. That can't be good.

"Hi guys," Barton says as he walks up to them. He sounds way too perky. Steve looks at him and Darcy dubiously. James raises one of his eyebrows at Barton in question. "I found her bashing heads in with the bat. She was by herself," he clarifies for them. Darcy still hasn't said anything, just gave them a short nod.

She's looking around the place they're staying at for now. Her face is no longer blank but James doesn't think the new look on her face is any better. "What's in the vials," he asks. The liquid inside the vials is a bright blue that also has a milky look about it. She turns to look at him; her eyes scan his body then do the same to Steve. She turns back to him.

"They melt people's faces and brains."

Steve and James take a step away from her at that revelation. "The liquid only reacts if you're infected. Something about the way the biology changes when they do. Jane-," her voice hitches on her name and that's all James needs to know. Knows that Foster and Lewis never went anywhere without each other. Though he's not sure why she was by herself. Figures she would at least have been with Thor or even one of the other scientists.

Her face shows the most emotion they've seen from her since her and Barton showed up. Her eyes show devastation, loss and- if he isn't mistaken- anger. After a few moments her face blanks again. Barton takes an involuntary step back when it happens. He looks a little panicked. She pivots on her heel and goes to sit on the ground and leans on one of the walls, staring into space.

"Like I said, she was by herself. I couldn't just leave her." Barton has a look of despair on his face. "I couldn't get anything out of her when I asked why she was by herself. I asked her where Doc Foster was and she pretty much shut down and said 'dead.' I didn't ask about Thor." They all look over at her to see she's watching all of them. Eyes going from face to face then roving around the room then back to them.

Steve looks back over to Barton. "Well she can stay. It's not like we're going to kick her out. Can she," Steve pauses, trying to find the right word. "…fight?"

Barton looks a little scared and haunted. "Yeah, I wouldn't worry about that." James is a bit skeptical but doesn't say anything. Steve just nods then straightens and tells them in his Captain voice he'll take first watch. He goes and sits on the ground, leaning on the wall opposite of the one Darcy is. Barton shrugs and goes to sit next to Darcy. James sits a couple of feet away from Steve. He doesn't want to accidently hit Steve in his sleep. He's quiet during his nightmares but he thrashes around violently.

James wakes up and sees that Darcy had moved away from Barton to sit on Steve's left side. They're both silent and they're eyes are constantly scanning the room. Barton has slumped completely onto the ground, not even leaning against the wall. His head is pillowed on Darcy's sweatshirt he thinks, snoring. He clears his throat and Steve and Darcy automatically start to reach for their weapons until they realize it's just him. "I'll take next watch," he tells them, his voice rough from sleep.

Steve nods his consent and leans back against the wall. He's asleep within less than ten seconds. When Darcy seems satisfied that Steve's actually asleep she gets up and walks over to him. She stands and stares at him, her head tilted to the side studying him. While she's looking at him he decides to do the same to her. Her hair is up in a sloppy ponytail and her glasses look like they're trying to slide down her nose. She's lost a little bit of weight since he last saw her but she still looks like a pin ups guys would hang in the barracks in the 40s.

He notices her looking at his left arm. His whole arm is showing from him wearing his uniform. It's what he was wearing when Steve, him and Barton got back from a mission and the world went to shit. He's just glad Steve wasn't wearing his Captain America get up when they got back. Though they are lucky he had his shield on him. It would have attracted too much attention. She's still looking at it when he curls his hand into a fist, the plates whirring. He's about to say something to her when she promptly sits on his right side.

His smile is bitter when he asks her if she's scared of his left arm. He follows that up with another question on whether or not she's slept not giving her time to answer the first. She doesn't look at him as she says no. "About the arm or sleep," he asks for clarification though he can see the shadows under her eyes.

"Both," she replies curtly then falls silent. She's still not looking at him but he believes her.

He's been on watch for two hours when he feels Darcy suddenly slump onto his right side. He looks over to see her asleep, her body leaning against his. He considers moving her so she's not against him but decides against it. He likes the way she feels leaning on his right side and she looks like she needs the sleep and he doesn't want to wake her by moving her.

She's not been asleep for very long when she starts moving around and mumbling. He looks at side of his body she's using as her bed when he hears what she's saying. She keeps saying 'I'm sorry' over and over. Then she really starts moving and her face flops into his lap. He has to move his hands quickly so her face doesn't land on them. When her flailing hand almost hits him in the face he wakes her.

She looks at him with confusion, her eyebrows drawing together like she's not sure how she got here. When she realizes what must have happened and her face is in his lap, she moves off of him. "Sorry," she mutters as she rubs her eyes and face trying to wake up.

"It's fine. Want to tell me what all that was about?"

She looks over at him obviously still trying to wake up. "Not really," she says and that's that. They go back to watching the room in silence.