At an event held at Los Angeles’ Hero Complex Gallery this week, Marvel head Kevin Feige and Avengers producer Jeremy Latcham gathered to celebrate the Blu-ray release of Avengers: Age of Ultron.

Flanked by an absolutely gorgeous new poster for the film designed by artist Tyler Stout, Feige and Latcham talked at length about The Avengers, their upcoming battle against the Infinity Stones and the evolution of their iconic roster moving into – and beyond – Marvel’s Phase Three.

By the conclusion of Avengers 2 and in the aftermath of Guardians of the Galaxy, it’s more or less clear where a majority of the all-powerful Infinity Stones have landed. Two, however, still remain a mystery.

“You will absolutely see the other two [Infinity Stones] sometime in Phase Three,” quips Feige. “After all, there’s a Gauntlet that needs to be filled.” But the careful connection between these massive films and the meticulous plotting required to fuel their meta-story has been a constant balancing act.

Cosmic Cube (Tesseract) in The Avengers

“It really began with Iron Man 2, building out the architecture for the entirety of Phase One. The notion of the Tesseract being not only the thing that ties Phase One together but that can also be a major part of Phase Two,” notes Feige. “I can’t say that it was all perfectly laid out in 2009, but that was certainly the genesis of it.”

“We always want the filmmakers to go and make the movie they want to make, not let the craziness of the world get in the way of that,” adds Latcham. “Afterwards, we can be certain that everything lines up and make those corrections. But the main thing is to allow each film to be as fun as possible…”

“For example, we always knew going into Age of Ultron that the stone in Loki’s scepter that would eventually end up in Vision’s head,” says Feige. Referencing Guardians of the Galaxy, however, he continues, “But others come out of more simple, structural plot needs. A filmmaker might say, okay, there’s a mysterious orb driving this story. At which point, we’ll suggest, alright, then let’s put something inside that orb.”

Loki Staff Mind Stone in The Avengers
MIND Infinity Stone (Loki's Chitauri Scepter)

And speaking of Guardians, Feige could not have seemed more enthusiastic about the upcoming, James Gunn-directed sequel.

“Certainly Thanos and the Infinity Stones are the connection between all these movies. Especially Guardians. When and if those specific characters start switching remains to be seen. The Guardians 2 team just left for Atlanta on Monday to start the movie, so all our effort and thought is going directly into that — which is shaping up very nicely right now.”

Ultimately, however, Feige categorizes Marvel’s plans for its massive Phase Three in two simple words:

“Broad strokes. Strokes that are broad enough and loose enough that – in the development of the four or five movies before we move into our culmination – allow us room to sway and move and surprise ourselves. All these movies, ultimately, should feel as if they were interconnected, all planned far ahead, and yet still pivot and breathe as individual films.”

And what will that Phase look like with new characters such as Black Panther, Doctor Strange and the return of Ant-Man still on the horizon? Latcham warns:

“Phase Three is definitely an end to some version of the team we’ve come to know as The Avengers. The team will always be evolving. The roster is always changing. You may pick up an Avengers book ten years later and not recognize the people on the cover…It’s not going to be the end of the Marvel cinematic universe, certainly, but it will be an end to part of it.”

With Feige taking charge and actor interests in staying involved in the MCU changing as we go (see: Robert Downey Jr. and Chris Evans) much of this is up in the air. Nonetheless, during the Q&A, Feige explained that they plan ahead with broad strokes how to handle each situation, whether they have certain actors and characters or not.

Next: Other Characters Marvel Should Introduce in Captain America: Civil War

Captain America: Civil War opens in theaters May 6, 2016; Doctor Strange – November 4, 2016; Guardians of the Galaxy Vol. 2 – May 5, 2017; Spider-Man– July 28, 2017; Thor: Ragnarok – November 3, 2017; Avengers: Infinity War Part 1 – May 4, 2018; Black Panther– July 6, 2018; Captain Marvel – November 2, 2018; Avengers: Infinity War Part 2 – May 3, 2019; Inhumans – July 12, 2019.