Seriously, watch the damn episode. On the thinking level-it's about how evil is not restricted to the supernatural and that humans are perfectly capable of doing bugfuck crazy things all on their own, which, given that the boys seek out that kind of thing, they are bound to run into every now and then.

On the shallow side-it has Sam in a skintight tee shirt kicking ass and flexing his biceps shortly after being locked in a cage and grunting/sweating/being sexy.

Watch the episode already.