After the diner, Castiel's desire to find answers grew more and more urgent. Using his angelic power, he flew to a number of locations all around the same, desolate town. To the human eye, it would appear he, as Dean would say, teleported. It wasn't that he did it for speed, but it was to him as walking is to humans.
He always found the way people moved to be peculiar, especially running. The fact that using two thin supports to hold up a weighty mass was incredible and displayed for him the power of God's ingenuity. Here in this strange place, it was going to be exceptionally useful.
Eventually, he landed in the street between the church and the movie theater. Each a place where people went to find understanding and answers. Unlike most churches, this one felt hollow somehow. Most churches filled him with a sense of communion with Heaven, but this one felt the same as the theater behind him. The notion was both unsettling and disheartening.
He needed to confer with Dean.
A moment later, he was back outside of Mickey's Diner. Instead of Sam magically appearing as Dean wished, he got Castiel, fully healed and more pensive than usual.