Thanos has arrived.

Although principal photography of Marvel's "Avengers: Infinity War" isn't scheduled to begin until November, directors Anthony and Joe Russo today unveiled a behind-the-scenes look at Thanos actor Josh Brolin dressed in his motion-capture suit. The accompanying text reads simply "Rehearsal."

In the photo, the Russo brothers appear to be chatting with Brolin, who's casually sitting on a platform in a spacious room lined with machinery and scaffolding.

thanos-brolin

Marvel Studios has spent more than four years seeding Thanos as the primary threat "in the Marvel Cinematic Universe, dating back to the 2012 release of "The Avengers." Loki's defeat in the film's climax looked to be an unmitigated success for the newly formed team of heroes, but in a post-credits scene, a mysterious character known as "The Other" met with Thanos to discuss the problem of Earth's Mightiest Heroes. That scene marked the Jim Starlin-created villain's entrance into the MCU.

Thanos didn't appear again until 2014's "Guardians of the Galaxy," where he was used sparingly (and mostly in hologram form), serving as an evil, intimidating presence throughout the film and coming into conflict with main villain Ronan the Accuser -- as well as his two adopted daughters, Gamora and Nebula. "Guardians" marked Brolin's first appearance as Thanos, as he did motion-capture and voiceover work for the film. Marvel Studios President Kevin Feige described Brolin as "totally intrigued" by the role and "a fan of what [Marvel Studios] did."

Since then, Marvel's films have continued to plant seeds for an upcoming showdown with the nihilistic Titan, best known for his love of Death (literally) and command of the Infinity Gauntlet. The various McGuffins present in the films (such as the Red Skull's Tesseract, Loki's staff and Malekith's Aether) were all eventually revealed to be manifestations of the Infinity Stones that power the Gauntlet, and in a post-credits scene from 2015's "Avengers: Age of Ultron," Thanos is shown to be in possession of the ominous glove.

The 2014 reveal of the "Infinity War" subtitle for the third Avengers film served as confirmation that the team would finally battle the mad Titan.

"Avengers: Infinity War" arrives May 4, 2018, followed by an as-yet-untitled sequel on May 3, 2019.