Castiel finally locates the Winchesters - trapped in some kind of construct that she can't simply phase through. There's a physical entrance she can access, though, and she does so. Wild applause and cheers echo from nowhere as Castiel enters the construct. It appears to be a... Japanese competition of some kind. Strange.
"Is this another trick?" Sam wonders.
"Cas," Dean says. "What are you doing here?"
"Looking for you. You've been missing for days."
"So get us the hell out of here, then!"
Castiel reaches for them both - knows it will be a stretch, with these prepubescent limbs - but before she can touch them, they vanish. The construct, or at least the physical aspect of it, has disappeared.
"Well, well, well," a voice says. "What do we have here?"
She loses time.
At some point, she spots an opening - another access point in the construct - and grabs for it without thinking. When she touches the doorknob something twists and shifts in her vessel, and she knows she's made a mistake - oh.
Taller, bigger, a familiar weight against her - his - his back and legs. Shoes just a little too tight, he'd forgotten about that.
No, she - he - she can't. He can't believe this, can't believe in this. It's not allowed, not for her. Him.
It's too real to be real.
He enters the construct to even more enthusiastic applause than before. He peers at the eerie emptiness that makes up one edge of the construct, but can't make anything out. Curious. Someone wolf whistles.
"Jimmy?" Sam gapes.
"Cas," Dean says, recognizing him instantly - an unexpected comfort. "You okay?"
Castiel feels, somewhere near him, a presence, and knows the creature that built this construct is almost upon him. "I don't have much time. Listen to me, something is not right. This thing is much more powerful than it should be."
"What thing - the Trickster?"
"If it is a trickster," Castiel says sourly. He has his suspicions - but he's shoved into a wall before he can voice them.
"Hello!" the supposed Trickster says, striking a pose in the doorway. He winks and preens for an imagined audience, then turns a mask of amusement on Castiel. "Hi there, Castiel!" A wave of his hand, and - no, no - Claire is hi-her vessel again. "There, now you look about as useful as you are!"
The whole thing was an illusion, a too convincing one. Too good to have been done by a trickster. An angel of the higher castes, on the other hand... Castiel narrows her eyes at him, trying to see past the facade. "You..."
Another wave of his hand, and her mouth is tied shut with a pink ribbon. "Children should be seen, not heard." The Trickster-angel turns to the emptiness of the construct's fourth wall and says, "But really, even seeing this kid is more than I can take. Shoo!"
The physical vanishes again - but now that she's looking, Castiel can see it. The subtle variation in waveform that this angel is trying so desperately to hide. It doesn't make sense - but there's no doubt in her mind now.
The missing archangel. Gabriel.