The Lost Crossover: When Supernatural Met Stargate SG-1

The Crossover That Almost Was a Deep Dive into the Cancelled Supernatural and Stargate SG-1 Movie

For years, both Supernatural and Stargate SG-1 have had dedicated fanbases, and for good reason. With their shared production roots—both helmed at times by key figures such as Robert C. Cooper, Brad Wright, and even the legendary Richard Dean Anderson in an executive role—it’s no surprise that rumors of a crossover swirled behind the scenes. What fans don’t know is just how close we came to getting a direct-to-DVD crossover movie that would have bridged these two iconic universes.

Tentatively titled “Supernatural: Gatekeepers”, the film was scripted in early 2014, planned for release between Supernatural seasons 9 and 10 and sometime after Stargate SG-1: Continuum. It would have featured Sam and Dean Winchester teaming up with none other than Colonel Jack O’Neill, Daniel Jackson, and Teal’c—alongside everyone’s favorite trenchcoat-wearing angel, Castiel.

So, what happened? And why did this ambitious crossover never see the light of day? Let’s break it down.

The Storyline: Ancient Gods, Fallen Angels, and a Tear in Reality

The plot revolved around an ancient artifact—one that shouldn’t have existed on Earth. The movie would have opened with an SG-1 mission to retrieve a lost Goa’uld relic that had been buried deep beneath the ruins of a temple in Iraq. However, when Daniel Jackson’s team unearths it, things go sideways—violently. The artifact activates on its own, releasing an unknown energy signature that alerts not only the Stargate Command but also the angel Castiel, who immediately senses a cosmic wrongness.

Meanwhile, in Kansas, Sam and Dean Winchester investigate a series of disappearances tied to a supposed “haunted military facility”—which, of course, turns out to be none other than Cheyenne Mountain. Unbeknownst to them, a rift between dimensions has opened, drawing in creatures not just from Hell, but something far worse.

The twist? The artifact wasn’t Goa’uld at all. It was an ancient failsafe left behind by the Furlings—one of the four great Stargate races—designed to prevent celestial beings from interfering in human affairs. The rift had begun pulling both Goa’uld symbiotes and supernatural entities into our world, fusing some together in monstrous, horrifying ways.

Cue the entrance of Colonel Jack O’Neill.

Jack O’Neill Meets the Winchesters

One of the film’s biggest selling points (at least, according to the leaked script treatment) was the dynamic between Jack O’Neill and Dean Winchester—two of television’s most sarcastic, authority-bucking heroes sharing the screen. Upon first meeting, their exchange would have gone something like this:

Jack O’Neill: â€œSo… you’re the guys hunting ghosts?”

Dean Winchester: â€œHunting ghosts, demons, things that go bump in the night. You know, just another Tuesday.”

Jack O’Neill: â€œNeat. We usually deal with aliens. Some of them are snakes. Some of them explode. Some of them explode and are snakes. So, you know… don’t touch anything.”

Despite their initial skepticism about working together, the urgency of the situation forced them into an uneasy alliance. Sam, naturally, found an immediate intellectual equal in Daniel Jackson, the two bonding over ancient texts and linguistic puzzles. Meanwhile, Teal’c and Castiel formed an unlikely pair as stoic warriors with more in common than they first realized.

Teal’c: â€œYou are an angel?”

Castiel: â€œThat is correct.”

Teal’c: â€œAre you aware that your abilities defy several known laws of physics?”

Castiel: â€œYour existence also defies several known laws of physics.”

Teal’c: â€œIndeed.”

The Villain: Anubis’ Return? Or Something Worse?

Where things got especially interesting was the true antagonist of the film. While early leaks suggested that Anubis—one of SG-1’s greatest villains—might make a return, the actual big bad was even more terrifying: a fallen angel fused with Goa’uld technology.

Named Ras’tiel, this hybrid being had once been an angel cast out of Heaven, its grace corrupted by ancient alien science. With the power of a Goa’uld symbiote and the celestial knowledge of an angel, it planned to reshape reality itself—merging both Heaven and the Stargate network into a single dominion under its rule.

The climax was set in Antarctica, at Earth’s second Stargate, where Ras’tiel attempted to use the combined energy of angelic grace and wormhole physics to rewrite history itself. It took a last-minute, desperate alliance between Castiel and Sam (channeling the knowledge of the Men of Letters) to sever Ras’tiel’s connection to the rift—while Jack O’Neill and Dean provided air support (read: explosions).

In the final battle, Castiel was almost lost to the void, but Teal’c managed to save him at the last second, cementing their begrudging respect for one another.

Why It Was Cancelled

So, why didn’t we ever get to see Supernatural: Gatekeepers?

Despite enthusiasm from both showrunners, the project ultimately fell apart due to a mix of budget constraints, licensing issues, and creative disagreements. The film had been conceived during a transitional period for both franchises—Stargate SG-1 had effectively ended with Continuum, and Supernatural was deep into its post-Kripke years. There was also concern that the film would complicate established canon, as the Stargate universe had generally avoided supernatural elements in favor of sci-fi explanations.

There were whispers that Richard Dean Anderson was hesitant to return for a direct-to-DVD project, though other sources claim he was fully on board. Regardless, by 2015, the project had been shelved indefinitely.

The final nail in the coffin? MGM’s rights to Stargate were in flux at the time, making a Supernatural crossover legally complicated.

Could It Still Happen?

While the odds of Supernatural: Gatekeepers ever being made are slim, there’s always hope. With both franchises now under the Warner Bros. umbrella (MGM having been acquired by Amazon, which has licensing deals with Warner for certain properties), a revival isn’t completely out of the question.

Plus, with Supernatural continuing to expand via spin-offs (The Winchesters) and Stargate potentially gearing up for a new era under Amazon, a crossover event could still be viable—perhaps even as an animated special or a novelization.

Until then, all we can do is imagine what could have been: Dean Winchester trading one-liners with Jack O’Neill, Sam and Daniel Jackson geeking out over ancient texts, and Castiel and Teal’c stoically saving the world.

Supernatural: Gatekeepers may never have made it to DVD, but in the hearts of fans, it lives on as one of the greatest crossovers that almost was.

Would you have watched it?