Barnes has three more fits before the end.

Dum Dum sits with him through each one, trying to be a comforting presence, though he has no idea what to do to make it better. A little part of him dies each time he watches Barnes convulsing miserably on the ground, sleeve shoved between his teeth, trying not to scream.

Sarge won't say much about what happens when he's like this, but when Jones pressed for information he'd finally, reluctantly, told them that it feels like his body's trying to turn inside out. Like his bones want to be outside, his skin is shrinking, trying to sink back into him. He said his veins burn like they're going to explode, and his heart pounds a crazy rhythm in his ears until he can barely hear a thing. Jones had listened to Barnes' heartbeat and lungs carefully, worried about lasting damage, but there'd been no sign of trouble to be heard. The kid, true to his word, seemed perfectly sound, and Gabe couldn't begin to account for it.

Dugan watches as Barnes comes out of his latest fit; the bone-cracking tension in his limbs slowly letting go as he droops with now familiar relief. It's finally over.
...At least until the next one.

"Look, Sarge, I know you don't wanna hear this…" he says quietly, as Bucky leans over himself, hands braced against his thighs, and catches his breath. "But you gotta tell Cap. Y'need help, kid..."

"No." Bucky wheezes, barely glancing up at him. There's a tightness around his eyes that says he's still in pain, but it's fading now. He'll be right as rain in a minute or two.

"Barnes-"

"Said 'no', Dugan."

"It's gettin' worse."
He lays it out bluntly, because he knows how Bucky is. Hard headed jackass that won't listen to sense unless you bludgeon him with it.
And the fits are getting progressively worse. He can tell by the way Barnes twitches with his entire body. How he chokes on his own swallowed screams like they're laced with broken glass. By the way that he staggers as he's trying to get up afterward. Dum Dum's doesn't know how much worse they can get, but he's pretty sure he doesn't want to.
"You know it is."

Buck freezes, then slowly straightens up. There's an mix of fear and outright hostility in his eyes.
"I'm handlin' it." he says coldly.

"Barnes, please-"

Bucky pushes off of the tree he's supporting himself on and starts moving back toward basecamp. His steps are a little jerkier than usual, but then he's not quite recovered yet. He probably will be by the time he hits camp.

"Buck..."

The kid hesitates for a moment, back to Dugan, then squares his shoulders and keeps walking.
Later, Dum Dum will never forgive himself for that. For letting Barnes walk away. *

He keeps his promise to the end though, and doesn't tell Rogers; even after Barnes falls. What's the point in spilling, now that the kid's gone?

He hates himself for that too.

A/N: * Borrowed these two lines almost verbatim, because they were too perfect to be improved upon. Credit where it's due.

END OF PLOT INTERLUDE