'Supernatural' spoilers: Castiel wants to become a hunter, Winchesters remain skeptical

While he's certainly an ally, Castiel's role in "Supernatural" has never been the same as the Winchesters'. Castiel is usually more embroiled in the mythology and the broader, season-long arcs, while the Winchesters deal with the the more day-to-day standalone hunts on their own. When he returns from Purgatory, though, Castiel is over the whole angel thing -- and he wants to join the boys on the road and become a hunter in his own right.Suffice to say, Sam and Dean have their doubts. In the episode "Hunteri Heroici," which airs Wednesday, Nov. 28 at 9 p.m., they reluctantly agree to investigate a case that Castiel has found, in which a man's heart burst through his chest. Literally.If that sounds like something that happens on a cartoon when a pretty girl walks past a lusty dude... you're pretty much on the right track. The Winchesters and Castiel happen upon a town where cartoon physics have...