They remind Sam of ants. The large Midwestern kind, the kind that had lived in the walls of a Michigan apartment that had been his when he was seven--the one with the basement that flooded. Those ants had been large enough to be a little bit smart, and would windmill chaotically when you found them, only to relent, regroup, resurge when you were least expecting it. After they put down the first wave, the zombies don't keep coming.
Sam can see flashes, though. Shy movements in the treeline. He's seen at least one zombie kneel at the mouth of a grave, stroke a tombstone. He doesn't want to think about what that might mean, who these zombies become if they aren't just here to rend flesh. But then, Sam's attention had snapped quickly elsewhere. When he turned back, the tombstone zombie was gone. Maybe they can't tell flesh from stone, and that's all it is.
Maybe it's not.
They've circled back to center, though Cas is nowhere to be found--nor is Jack's body. Just the singe of his wings.
Dean limps over to the tombstone he'd halved with his body, collapses onto its stump, and instantly looks the worse for it. His body goes rigid-still, and when he jerks to his feet again, it's clear he's found his pain and it does not go away. He wipes the rust and blood from his palms
and sets out skulking in a figure 8 around Sam, around Jack's wings. He mutters something about, Oh, that's great. Lose the angel and Where the fuck are you.
Sam's world tilts trying to follow Dean's trajectory, his heart beating in his shoulder heavy until it seems like it's not beating anywhere else. Sam sees white for a moment, then black, then pointillized color on black. Then Dean. Then graveyard.
"How's your--" Dean starts. "Uh, multidimensional wave... hole."
One-shouldered shrug. "No shrapnel. So there's that."
"Good," says Dean. His voice sounds feathery. The sudden quiet, the riptide of adrenaline funneling away, is doing him no favors. He's limping worse, but he clearly wants to run. Wants to keep swinging, keep momentum. He doesn't know what will happen if he stops. Dean makes mud tracks over the wings until it's impossible to tell what they had been.
It doesn't really feel like a bullet wound. It's… weird. It feels like his shoulder is trying to pull away from him, somehow, or get sucked in. Feels like it's taking his brain with it, to some black hole nowhere. It makes Sam want to sleep. Never wake.
"Sammy," says Dean, feathery.
They keep going.