This was a really good episode. With the introduction of Cain, along with the revelation that Gadreel was responsible for letting the serpent into Eden, I wonder if they will be exploring the mythology of the Old Testament in greater detail. Perhaps we'll meet Abel, or Adam and Eve. They might be planting the seeds for the return of God in the series finale. Funny you should say that. I was thinking along those lines back around season two, but then things seemed to change when they started getting extra seasons.