I do not own The Avengers or anything associated with it. This was a prompt from Tumblr, which is why it's so short. Also, first canon thing I think I've ever written.
She sits by his bed for a long time before there is any sign of movement - she must have hit him harder than she thought - but when he finally does open his eyes, they are their normal blue. He gives her a small smile, the smile he only ever gives to her, and breathes her name.
But his eyes become illuminated with the power of the tesseract again and he slips away. Her name becomes a plea for saving, a cry for help.
He fights it for almost an hour, his eyes flickering between shades of blue, the violent shade of tesseract control startling her nearly every time. His body pulls against the restraints. He looks at her with fear in his eyes.
When the tesseract seems to be almost gone, she moves to sit on the bed, one of her hands finding his. She holds on tightly. She doesn't say anything, just holds on, but it is more than enough. He returns the grip best he can while still strapped to the bed. He closes his eyes, inhales a deep breath and exhales her name. She tightens her grip. She fixes his eyes with hers and tells him to keep fighting, that she isn't going anywhere.
His eyes brighten and he looks at her with the same impassivity with which he observes his targets. She suppresses a shudder but doesn't let go.
It passes.
He asks her why she doesn't leave him to suffer; he deserves it after what he's done. She tells him to stop being an idiot.
It comes again and he asks her if she knew it would be all right. How she knew. Why she knew. He asks her if that was what she knew.
Then it passes.
And it doesn't come back.
Slowly, she removes his restraints, her body tensing in case he attacks her, in case the tesseract isn't really gone from his system. Her fingers move over his wrists without much of a thought, tracing the area that had been restrained. He calls her name softly and she looks up, finds his face full of regret and sadness.
She places a hand on his cheek, just for a second. He captures her hand as she tries to move it away and holds it there, turning his face into her palm, his lips meeting her skin for a fraction of a second.
She whispers his name, the word full of desire and regret.
He lets her hand go. It rests on his leg for a moment.
He sits up and turns so they're sitting with their arms touching, their hips, their knees. They gaze at each other, their minds wandering through their shared history back to the beginning, to the one decision he'd made that kept her alive.
She leans a tiny bit closer to him and he moves into her. He moves his fingers between hers where their hands brush.
It's her turn to breathe his name.
His lips brush her forehead as he whispers thank you, thank you for saving him, for bringing him back, for hitting him on the head.
She laughs quietly as she lifts her head.
Their noses brush and a thrill runs through her.
They've done all this before, but every time it's like something new, something waiting to be discovered. They've done this as part of a cover, as friends, as more. It never stops. Never gets old.
They inhale and exhale together. His lips brush hers lightly, but neither of them move to take it farther. Not yet.
But the promise is there.
The promise for when it's all over.