Season 6 of Supernatural marked the start of a new era in the show's history. Having put a pin in the apocalypse at the end of Season 5 -- and now down by one (and a half) Winchester brothers -- Sam and Dean's adventures appeared to have come to a close, as originally laid out by creator, Eric Kripke. Sam went to Hell, Dean went to suburbia (his own personal hell) and Kripke moved on. And then, surprisingly, so did the show.

Even with old hands, Sera Gamble and Robert Singer, staying on board to steady the ship -- and Kripke credited in a consultant role from Season 7 onwards -- the transition period was a choppy one, as can be the case when creators step away from their creations. Where is there to go when you've stopped the end of the world and caged the Devil? The answer, as it turns out, is straight through the fourth wall.

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In "The French Mistake," (named as an homage to a scene in Blazing Saddles that is interrupted by two characters bursting onto the set), Sam and Dean are put in what can best be described as interdimensional witness protection by the angel Balthazar to spare the boys from becoming casualties in the civil war brewing between Castiel and rogue archangel Raphael. Balthazar hides them somewhere he hopes will be well out of his superior's reach: an alternate universe. There, Sam and Dean find themselves dropped onto the set of a television show called "Supernatural," a place where everyone thinks they're two actors called Jared Padalecki and Jensen Ackles, rather than two, plaid-wearing hunters of the paranormal.

But the meta fun doesn't stop there. Surrounding the confused brothers are a cast of familiar names: Bobby Singer (Sam and Dean's surrogate, curmudgeonly father in their universe) as well as stand ins for Robert Singer and Sera Gamble. "Eric Kripke" is called in when the crew becomes concerned about "Jared" and "Jensen"'s odd behaviour and, appropriately but somewhat cruelly, dies at the hands of an assassin sent by Raphael.

Castiel, or rather, "Misha Collins," is also present; demoted in this world from a humorless angel of the Lord to a tweet-happy actor desperate to ingratiate himself into his co-stars' good graces. Rounding out the cast is Genevieve Padalecki, wife to both "Jared Padalecki" in the episode and actual Jared Padalecki in real life. The two met on the show when the actress played the second iteration of the demon Ruby. "You married fake Ruby?" Dean asks Sam incredulously.

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Supernatural already put some dents in the fourth wall in the Kripke era by introducing the "Supernatural" books, a novel series about Sam and Dean's exploits penned by the author Carver Edlund, who was really the prophet Chuck Shurley, who was really God taking a few decades worth of vacation days down on Earth. This Season 6 episode, however, demolishes that wall entirely, and gleefully.

The best parts are the smaller details, creating layers upon layers of self-referentiality: Dean scoffing at real footage of Jensen Ackles on Days of Our Lives; Misha Collins sending real tweets as "Misha Collins" and the commentary on Jared and Jensen's preening: "Look at these male modelin' sons of bitches." It does, however leave some semblance of fantasy in tact as we learn this world couldn't possibly be ours as it's one in which Jared and Jensen hate each other. In reality -- our reality -- the two are very close.

Aside from being a classic example of a good old Supernatural filler episode, "The French Mistake" can also be looked back on as a starting point for the show's expansion away from the horror genre into broadly fantasy/sci-fi. In one of the series' rockiest seasons, Sam and Dean stumbling into the multiverse blew Supernatural's story possibilities wide open.

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