Check out the official guide for Supernatural Season 7 Episode 21, “Reading Is Fundamental,” in which Castiel awakens from his coma, airing May 4 on the CW.
CASTIEL AWAKENS FROM HIS COMATOSE STATE
- Meg (guest star Rachel Miner) calls Dean (Jensen Ackles) and Sam (Jared Padalecki) and tells them Castiel (guest star Misha Collins) is awake and talking.
- Meanwhile, a teenager named Kevin (guest star Osric Chau) gets hit by a bolt of lightning and is turned into a reluctant prophet.
- Sam and Dean believe Kevin holds the key to defeating the Leviathans but must fight off two Archangels who want him for their own purposes.