Darkness.
Cold.
He is dead.
Castiel drifts in that thought for a moment.
No, the darkness and the void do not consume him completely. But he cannot see, can only hear in fuzzy vibrations against his flesh. Cannot move, can only wriggle this casing of skin and juices around him. It is become him. He is an earthworm.
Castiel opens his eyes. His eyes... they contract sharply against the light and he squints them shut again. They only see in echoes - the darkness is friendlier. But he cannot move, and he feels the fragile heart beat faster unbidden, squeezing into his throat, twisting into his chest and constricting it, and he almost cries out, but he has no voice and there is no one who could hear it, for his brethren are...
...there is no one else in all his world. There are only these other scurrying creatures who he once admired but who will never see the cities outside their earthen womb or comprehend the songs he has sung, who could never hear or ever pronounce his true name.
He cannot speak his own name and suddenly he knows and his borrowed spine is ice in his flesh and his stolen guts are frigid water.
A rush of longing, of misery rushes over the surface of his panic and he tries to reach out for comfort, to reach beyond but of course he has no arms except these prostheses of nerve and bone and they hardly move.
There is a moan, a voice that grates strangely inside his skull. He sluggishly recognizes it as his vessel's; his own. It makes him pause. He opens his eyes.
Fist. Palm. The slow curl of fingers. This is familiar. This body has been his vehicle for months. He can no longer control it with a thought, but already as he studies his shaking hand, it begins to slow and calm. It is only himself, his wings, his grace, he is an amputee, blind, he cannot... stop. Stop.
The thought is a wall against a sea of terror. He can feel the deep behind it, but he pushes back. Commands it back. This body is too sensitive to turmoil, too difficult to control, and besides, there is something...
Dean. Sam.
Castiel tries to stretch his wings before he remembers.