Production has been under way on the highly-anticipated video game adaptation Assassin's Creed since mid-September. We've already seen our first look at Michael Fassbender as Callum Lynch, along with set photos that tease Abstergo Industries' involvement in the story. Unfortunately, we haven't seen any set photos with Michael Fassbender in action. But today, the actor's production company DMC Film released a seemingly innocuous photo that teases a new detail about this mysterious character.

While we can't see the actor's face, Michael Fassbender is seen in costume as Callum Lynch, looking at a sign that reads "Progress requires sacrifice." If you look closely, though, you can see three marks on the back of his neck, that form a triangle. One Twitter user, Mike Wagner, reached out to Assassin's Creed Head of Content Azaïzia Aymar, theorizing that the marks may either be from the "Animus," or "he's doing that burning cup thing." While Azaïzia Aymar wouldn't confirm either of those scenarios, he did respond with "good guess!"

RELATED: Michael Fassbender Knows Why His Assassin's Creed Movie Bombed

In the Assassin's Creed video game, Animus is a virtual reality machine developed and sold by Abstergo Industries. This device allows the user to project the subject's memories onto a screen in three dimensions. Abstergo also sold a console version of Animus, sold commercially as an entertainment console, that doubled as a tool the Templars used to spread their influence. We know that Abstergo will be a part of the story somehow, but it remains to be seen whether these marks come from Animus or not.

The supporting cast of Assassin's Creed includes Marion Cotillard, Ariane Labed, Michael K. Williams, Carlos Bardem, Denis Menochet. Brendan Gleeson and Jeremy Irons are the latest casting additions, coming aboard earlier this month to play the fathers of Marion Cotillard's character and Michael Fassbender's Callum Lynch, respectively. It isn't known how much filming is left on Assassin's Creed at this time.

Back in August, it was revealed that the Assassin's Creed adaptation is set in the same video game universe, with the game franchise's head of content, Aymar Azaizia, teasing that "familiar faces" from the games will pop up in the movies. No other characters from the games have been confirmed at this time. Justin Kurzel is directing from an adapted screenplay by Scott Frank, Michael Leslie, Bill Collage and Adam Cooper. Frank Marshall, Arnon Milchan, Jean-Julien Baronnet, Conor McCaughan, Fassbender and Pat Crowley are producing. The project is based on the wildly popular Assassin's Creed video game series, which has sold over 91 million units since it was first launched. While we wait for more details, check out the latest photo from the Assassin's Creed set.