As per usual, Supernatural takes liberties with the Biblical record of events. In this version, Cain is actually the hero -- sort of. He only becauomes evil in order to save his brother from an eternity in Hell. Although, as far as taking liberties with Scriptural accounts, Supernatural has done worse. And, as usual, Omundson is phenomenal.
Meanwhile, the Winchester relationship is still fracturered, and continues to be the underlying theme of the season. While Castiel tries to help Sam overcome his bitterness against Dean, Dean is reminded that hunting with Crowley means always having to watch your own back.
The only downside to the plot at this point? As much as the grudge between Sam and Dean is well written and acted (and well deserved), it's also taken just about as many episodes as it can before getting annoying. This isn't the first time the brothers have fought, and we all know the they have to work together if they ever want to win their fight against Abaddon or the angels. There are more than enough villains in this season without the Winchesters fighting each other.
