So Supernatural did a “Wizard of Oz” episode. It’s not unheard of for a show that been running for 9 years to do gimmicky episodes like this. Hell, back in season six Supernatural did a western episode. And all the prerequisite “OZ” references are present and accounted for: black and white sequence? Check. Crowley whistling somewhere over the rainbow? check. Jokes about heel-clicking, calling someone Toto, dropping “there’s nowhere like home” at the end? Check, check, and check. Somehow, despite the inherent hokey element that can easily prosper in an episode length gimmick like this, “The Winchesters of Oz” manages to turn that gimmick into a solid episode that advances the plot, brings back some of the humor that more recent seasons have been missing and homage the classic film in ways the remain consistent with the tone and aesthetics of the show.
Naturally the cold open of the episode features a black and white flashback to the original Men of Letters (a secret society of scholars well versed in magic/ monster lore) to inhabit the underground M.O.L bunker the Winchesters have made their new home base. They grapple with the boredom of being confined to bunker duty when Dorothy, who is actually a hunter (and daughter L. frank Baum, a Man of Letters) barges into the bunker with an incapacitated Wicked Witch in tow seeking a way of destroying her. Flash forward to technicolor present day where hunters Sam and Dean Winchester have discovered a 60+ year old Men of Letters computer. This leads them to call in Charlie, the Hacker/ computer programmer turned Hunter played by recurring guest star Felecia Day. Unknowingly however, they undo a binding spell cast by Dorothy confining her and the wicked witch in a jar near the computer. With the dominos set in motion, a game of cat and mouse erupts in the corridors of the Men of Letters Bunker.
Throughout the episode we get an increasingly vivid idea of e layout of the Winchester’s new “bat cave” (previous use of the set was primarily restricted to the main lobby, the dungeon where Crowley is being kept and Sam and Dean’s bedrooms). For instance we now know that it has a kitchen, a network of hallways and corridors most likely leading to rooms filled of cool supernatural stuff and even a garage full of 1950’s cars and motorcycles (complete with an underground tunnel road leading out of it). Oz is incorporated into the Supernatural mythology by establishing it as fairy realm (a smart move as fairies have been featured at least twice throughout the series), building off the idea of L. Frank Baum as a Man of Letters with his daughter Dorothy as a hunter, this resulting in a feasible way rationalizing an entire “wizard of oz” themed episode without it coming off as overtly gimmicky. Preexisting plot lines are still present in the form of Ezekiel (the angel inhabiting Sam’s body, unknown to Sam) who makes an appearance to revive Charlie after she is killed by the Witch. This scene actually establishes multiple things for the show. Ezekiel makes it known that he is still weak and cannot be expected to keep reviving people (he had healed a mortally wound Castiel in the previous episode), thus nipping this plot device in the bud before it becomes falls plot holes/ convenience deux ex machina territory. Through Charlie we learn that Heaven is still accessible by human souls despite the all the angels getting cast out by Metatron. Both Crowley and Ezekiel demonstrate an apprehension of the witch, establishing fairy beings as very powerful, even when angels and demons are thrown in the mix.
This is where the episode succeeds, yes, the references and homages are there (they even worked in the ruby slippers, though they’re merely red stilettos and are never named) but it still makes sense as an episode of Supernatural. All the references and homages are tied into preexisting precedents within the show in way that it comes off as natural. This episode could have easily gone very wrong, but the attention to detail and continuity make for a fun, memorable hour of monster hunting.