Josh Brolin has teased Thanos’ quest to find the Infinity Stones in Avengers: Infinity War on Instagram.
In the comics, said Stones are typically sought for reunification with The Infinity Gauntlet by the supervillain Thanos; who turned up as the surprise mastermind behind Earth’s recent troubles in the aftermath of The Avengers.
Some rumors have suggested roles for characters from the MCU’s popular Netflix series, but have been repeatedly denied by those involved.
While the actual film-to-film connections between the Marvel Cinematic Universe have (for the most part) been looser than some other shared-continuity experiments, typically coming in the form of guest-appearance cameos, references or after-the-fact tie-ins; one element has been in play since the earliest days of Phase 1 – albeit not revealed as such (via retcon) until after the fact: The Infinity Stones, a set of power objects originating as ancient cosmic ingots said to possess unfathomable powers.