Supernatural may be a show about two ghost-busting brothers, but one of those brothers—Sam Winchester—didn't even know ghosts existed in the first version of the show. The show has become a CW institution after lasting for 15 seasons and almost 15 years on the network and will air a bittersweet series finale this month. The appropriately titled supernatural drama follows brothers Sam and Dean Winchester as they travel back-and-forth across the country hunting various fantastical foes.

Sam and Dean come from a family of ghost-hunters and, despite some initial resistance on Sam's part, find themselves running the family business after the death of their mother and disappearance of their father in season 1. Supernatural uses a procedural structure to tell its stories that has Sam and Dean chasing after a different ghost in each episode as their season arcs progress. Other out-of-this-world shows that came before it like Buffy, the X-Files, and Charmed also used a similar monster-of-the-week model in different ways. Where creator Eric Kripke's dramedy sets itself apart is its focus on the relationship between Sam and Dean as they work through familial issues while ghostbusting. Their fraternal bond is an endless source of both drama and unexpected comedy—Sam and Dean rag on each other as only siblings can, a rapport perfected by Jared Padalecki playing a chronically self-serious Sam and Jensen Ackles as Dean, by turns heroic and buffoonish.

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It's hard to imagine what Supernatural would look like without the Winchester brothers fighting monsters side-by-side, but Kripke told EW that Sam didn't even know they were real in the original version of the show. In the first draft of the show's pilot, Sam was kept in the dark about the existence of ghosts growing up, while Dean was the only brother who knew the truth. Proto-Dean was a lone ranger and hunted ghosts without help while Sam 1.0 was confused by and afraid of the unknown paranormal evils Dean came up against. Kripke admits the premise wasn't a winner:

Dean was always the troubled kid who went out and found and is now bringing Sam back in it. [The idea was] so stupidly complicated, and it was all super-dull. So then I turned it in and at the time I was like, "Nailed it!"

Sam and Dean show their badges

He submitted the pilot to Warner Brothers, where Supernatural eventually debuted before moving to the CW after a season. The script was rejected, but the WB gave Kripke a shot at a second draft. When he realized that the brothers' relationship should be at the center of the show, everything else fell into place. The creator also says that his first version of the pilot was too serious because he was trying to make it genuinely scary, which ultimately resulted in a boring story riddled with cliches. Making Sam and Dean ghost hunters by trade meant they didn't have to be scared and surprised by the show's big bads, which allowed the characters to take everything a little bit less seriously.

Although it seems a far cry from the Sam fans have gotten to know after 15 seasons, a Sam who's unfamiliar with the family business isn't so different from the version on the show. Dean, the older of the two, is more aware of their father's profession and feels responsible for protecting his younger brother. Sam doesn't learn about ghosts until later and has more freedom to develop his own ambitions. Both brothers ultimately find themselves entangled with the occult in ways that far exceed their job description, but unlike Dean, Sam is haunted by a feeling of disconnection from the brothers' mutual "calling" that proves ill-fated. In two weeks, Supernatural fans will see the Winchester brothers fight the paranormal (or holy, in this case) one last time.

Next: Supernatural Retcons Amara & God's Origin Story

Source: EW