'Supernatural' Would've Been "Destroyed" If It Used This Monster Storyline That Completely Changes Sam and Dean

Over 15 seasons, it's not uncommon for any show to suffer through some narrative pitfalls. When dealing with paranormal threats, for instance, it's quite easy to write oneself into a corner when you put your heroes up against villains like the Devil or the physical embodiment of darkness. This is exactly what Supernatural did in its last few seasons, and it's something of a miracle that the show came out on top at the end — even after a final season ruined by a boring, out-of-left-field retcon. But things were almost much worse for the Winchesters, as it turns out that the writers once entertained the idea of revealing the truth about monsters to the entire world.