The necklace, that which would burn in the presence of God, held tightly by a seraphim holding just as tightly to his faith, never warms. And Castiel cannot think why. He has been to every molecule of the Earth, and he has even searched the night beyond. Nothing.
He drops it in a trashcan, disgust and pain and disbelief.
Dean does not remember that in all of his life, it has been warm, just once. Or perhaps, it is better to say in all of his deaths.
For while in Hell, it heated against his skin. But he thought it to be the hellfire, and it was not long before it was cut away from him, just as blood and bone and skin were.
He would not have known, in any case.
That God would be in the Cage.