Few of Marvel’s secret credits scenes have meant as much as the one that came halfway through the closing credits of The Avengers, where the silent, smirking supervillain Thanos was introduced. The purple-hued Mad Titan is one of Marvel’s biggest bad guys, and his appearance seemed to portend two things for the Marvel Cinematic Universe: At some point, likely in the third Avengers film, Thanos will emerge from the cosmic shadows and fight all of Earth’s mightiest heroes, but in the meantime, he’d be collecting the stones that power up his Infinity Gauntlet, a golden glove that Thanos used in a classic comic-book storyline to wipe out half the universe and nearly every superhero.

Those are some mighty big shoes to fill, and speculation ran rampant on whom Marvel might cast as Thanos until last week, when word broke that Josh Brolin would voice the baddie in the studio’s buzzy, space-set Guardians of the Galaxy, out August 1. But how much will we see of Thanos in that film, and what will we learn about his plans to assemble all the Infinity Stones? Vulture can further lift the veil on the mysterious character’s machinations, but if you’d rather not be lightly spoiled, strap on some rocket boots and make haste now.

Though Thanos didn’t appear until the very end of The Avengers, Vulture has learned that he’ll emerge in the first act of Guardians of the Galaxy. Thanos will be communicating remotely via hologram for most of the film — a move the Mad Titan likely cribbed from the equally enigmatic Emperor Palpatine in The Empire Strikes Back — though he does show up in the purple flesh for a scene that also features Ronan the Accuser (Lee Pace) and Nebula (Karen Gillan), who do Thanos’s bidding and serve as the primary adversaries in Guardians. Still, though Thanos is only briefly glimpsed throughout Guardians, his presence is palpable throughout: Characters reference him often and fearfully, and he has familial ties to Gamora (Zoe Saldana), our green-skinned female lead.

The movie also presents another one of the Infinity Stones that Thanos is trying to retrieve to assemble his powerful Gauntlet. In the comics, there are six such items — gems that can manipulate Space, Mind, Soul, Reality, Time, and Power — and in the closing credits tag of Thor: The Dark World, the mysterious Collector (Benicio Del Toro) came into possession of one of them, the swirling Aether, and announced “One down, five to go.” We’ve likely seen two other Infinity Stones in the Marvel cinematic universe thus far — the glowing Tesseract featured in Captain America and The Avengers, which corresponds to the Space Stone, and Loki’s blue-hued, do-my-bidding scepter, which may be the Mind Stone — and Guardians offers a fourth, which Del Toro’s character helpfully identifies as the Power Stone. (Fans had previously speculated that the Aether might be the Power Stone; it’s now more likely that the mysterious, floating item from Thor: The Dark World will serve as the Reality Stone in this series.)

All in all, Guardians of the Galaxy should offer Marvel fans plenty of new developments and teases to pore over, though Thanos will retain his aura of mystery for a while longer: The purple beast will likely recede back into the shadows for a bit after Guardians, preferring instead to let the Avengers battle arch-foe Ultron (voiced by James Spader) in their second go-round Avengers: Age of Ultron, out next summer. After that, though, Iron Man, Thor, Black Widow, and the rest would be wise to fear what’s coming. Thanos has a plan, and it’s all beginning to come into focus.