“Into the Mystic” is a quiet Monster of the Week episode, complete with the usual guilt and introspection we’ve come to expect from Supernatural. After the action-packed “The Devil in the Details” and “O Brother Where Art Thou?” having a slower episode provides an opportunity to take in everything that’s happened. Sam just faced his old nemesis Lucifer while Dean is grappling with his complex feelings about Amara, hence the guilt and introspection. At least we can have some fun watching Lucifer as Castiel (Luciel, CaSatan, Castevil, Casifer?).