A video purporting to show an unused post-credits scene found within the files of Assassin's Creed Mirage may point to a seismic upcoming shift in series' story.

Filenames for the scene reference "Assassin's Creed Neo", an internal Ubisoft codename believed to refer to one of several upcoming projects currently in development. Thus, the big twist revealed here is expected to be something we see more of in future games.

For those who'd rather be left unspoiled, this is your last chance to turn away now.

A leaked video datamined by Sliderv2 shows a futuristic radio antenna hidden away in Mirage's ninth century desert, prompting the question of when this is actually set.

A surprising answer to this is heard in the clip's audio, which comprises a conversation between two voices labelled simply "Animus Operator", who are busy discussing the DNA memories that made up Mirage's story.

In a huge twist, the voices reveal they are from the distant future - as they refer to our 21st century present as "ancient history".

Present day Assassin leader William Miles is described by one of the Animus Operators as an "Assassin Mentor, one of the last before the Great Shift".

"The Shift was 21st century history," the second Animus Operator replies. "Ancient history."

Ubisoft is yet to verify this footage, though excited fans currently discussing the snippet do not doubt its veracity.

And while it would be a surprising move, it's nothing that would seem too outside the bounds of Assassin's Creed's already fairly wacky lore. (Remember the original plan to end Assassin's Creed 3 with Desmond blasting off on a spaceship?)

Of course, the fact this was removed from Mirage's final release begs further questions. Why was it cut? Did Ubisoft decide to change course? Or was this simply too spoilery, too soon?

The video itself - likely by design - provides more questions than answers. Exactly what the Great Shift is and who these people remain unknown.

What is known is that future Assassin's Creed projects will be part of a more cohesive ongoing narrative, told through the upcoming Assassin's Creed Infinity platform/hub/launcher thing set to debut alongside the next major release in the series. (That's currently the Feudal Japan-set Assassin's Creed Codename Red, which fans expect to launch in 2024.)

Speaking to Eurogamer, Assassin's Creed boss Marc-Alexis Coté previously described the launch of Infinity as "a momentous change for the franchise".

"We will be better caretakers of our meta story," he said, referring to the often meandering, piecemeal modern day narrative revealed over the series so far. "And this hub will help us accomplish that promise."

Moving the "modern day" portion of Assassin's Creed into the future would certainly be a momentous change - something that could reignite interest in the series' metastory, while also acting as a soft reboot to give Ubisoft some space from 15 years' worth of narrative baggage.

It would also present players with a brand new mystery to uncover - what has happened between our present and whenever these voices are set? What is the Great Shift? We've contacted Ubisoft for more.