Castiel only went back to the car for a few minutes. He left Dean observing the vampire nest from a distance, gaining intel on how many were inside, but now he's nowhere to be seen.
Cursing in frustration is one of the human habits that he's picked up over the years - and Castiel certainly does it now.
By the time he's made it to the front door he can hear chaotic yelling and snarling from inside, and the unmistakable whistle of a machete slicing through the air, followed by the thud of a head hitting the floor.
But it's not enough - Castiel can see how outnumbered Dean is as he rushes into the living room - and he barely has time to warn Dean to cover his eyes before he's letting loose a blast of Grace.
When the blinding light finally fades away Castiel let's out a long shaky breath, trying to hide how even just using that much power has made his hands tremble.
Dean opens his eyes again and looks around at the smoking bodies of the dead vampires with an impressed whistle. He opens his mouth to say something - no doubt some kind of witty anecdote - when his eyes widen at something behind Castiel.
There's a vampire there, holding his ribs, with one half of his face burned away, and he's got a gun held up. Pointed at Dean.
Castiel is too far away to push him, too weak to move quick enough to block the shot with his body, so on instinct he does the first thing he can think of - he flares out his wings wide.
Gunshots blast out into the room five times in quick succession, but instead of hitting their intended target they seem to hit an invisible wall. Castiel blames using too much Grace on the blast for how the bullets don't bounce off his heavenly limbs like they should, and have instead buried themselves into something that isn't even on this plane of existence. It should be impossible, but the bullets appear to be suspended in midair - caught in his invisible wings.
Pain unlike anything Castiel has ever felt blazes from the damaged wing, and a fast flowing stream of shining blue liquid pours out of the impossible wounds, pooling onto the floor. He grunts and falls to his knees, vaguely aware of Dean dispatching the vampire and gripping onto his shoulders tightly. At least Dean is okay. No bullets got through to him. Castiel thinks he can hear Dean saying his name, but his vision is swimming and everything is going dark. He can't pull the wing back in, he can't... Castiel glances across to the damaged wing and is shocked to see black feathers there instead of nothing. He hasn't ever seen his wings materialized onto the earthly plane before.
It's a silly thought to have while he's bleeding out Grace, but he wonders if Dean will like them. Black is a very unusual feather colour for an Angel.
But before he can ask, darkness finally pulls him under.
