Fresh off of the conclusion of The CW's big four-show crossover between "Supergirl," "The Flash," "Arrow" and "DC's Legends of Tomorrow," a former "Supernatural" production assistant revealed that the Flash and Green Arrow's original team up in 2014 almost wasn't the network's first superhero crossover. Jackson Stewart recalled that once there was talk of a crossover between "Supernatural" and "Smallville," The CW's long-running show about pre-Superman Clark Kent.

“There was a lot of really cool ideas that some of the writers had,” Stewart told Entertainment Weekly. “They had an episode where they really wanted to do a Superman curse that was about every actor who plays Superman ends up getting killed. So they find out that Tom Welling from 'Smallville' is next and have to save him. I thought that was one of the funniest ideas that I’d heard.”

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Of course, the episode never came to fruition, but it certainly wouldn't have been "Supernatural's" first meta episode. Now on its 12th season, "Supernatural" has found its main characters in an alternate reality where their lives are a fictional television series; the Winchester brothers have also attended fan conventions based on their adventures, as captured by a "prophet" who wrote about them and published his works in book form. A tongue-in-cheek reference to "Supernatural's" proximity to the "Smallville" set, then, wouldn't have been outside of the show's wheelhouse. What's more, since it wouldn't have impacted "Smallville's" storyline, the DCTV show wouldn't have suffered for any out-of-character or non-sequitur moments.

Additionally, the idea isn't entirely out of the question for "Supernatural" these days. After all, The CW has a few former Superman stars in their employ, including "Legends of Tomorrow's" Brandon Routh and "Lois & Clark" alum Dean Cain, who currently guest stars on "Supergirl." What's more, the network hasn't been shy at referencing Routh's history as "Superman Returns'" title character; Routh even dropped a scene-stealing joke about it in the last episode of "Legends of Tomorrow." Since Tom Welling's "Section 13" pilot wasn't picked up at CBS, the former "Smallville" star is currently a free agent.

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With a little tweaking, then, "Supernatural" could still pull off their original crossover concept. There are also plenty of other superhero TV shows to pick from nowadays, especially considering The CW is now home to four separate DCTV series. The odds of that may be slim, but we can dream!

Starring Jensen Ackles, Jared Padalecki and Misha Collins, "Supernatural" airs Thursdays at 9 pm EST on The CW. "Smallville" starred Tom Welling, Allison Mack, Michael Rosenbaum, Erica Durance and Kristin Kreuk and wrapped up its 10-season run in May 2011.