"That was the plan," Castiel agreed, frowning slightly. He had to admit his attentions had been elsewhere when it came to the plans that Sam and Dean made for hell. It was a regrettable instance, but he had been distracted with his own trials.
Not really trials.
"It was… my intention," he said, and sounded regretful even now. "I wanted to fix it. My home. Stop the fighting." Not a lot of things made him want to leave earth -- he felt he'd built a place with the Winchesters that little could replace. But he would have done it. "I was tricked, though." There was that awful smile again. Castiel as a human was quickly learning the fine art of self deprecation. "My grace was cut from me and stolen. Used as a spell that expelled all the angels from heaven."