DC’s big-ticket supergroup unites in the Justice League trailer that debuted Saturday, though director Zack Snyder has been working on forming this heroic team for much longer.

“The thing that’s awesome about these icons is that a lot of them we haven’t seen in the movies before on the big screen,” Snyder says of the newer superheroes in Justice League (in theaters Nov. 17) such as seafaring warrior Aquaman (Jason Momoa), cybernetic newcomer Cyborg (Ray Fisher) and the super-speedy Flash (Ezra Miller).

“It’s kinda fun to really let (the actors) stretch their legs and inhabit those characters,” the filmmaker adds. “It is a process to make a team out of this group of individuals, but for the greater good maybe they can put their differences aside.”

Snyder gave quick glimpses at the three rookies in last year’s hit Batman v Superman: Dawn of Justice, which brought together DC’s high-profile trinity of good guys: Batman (Ben Affleck), Wonder Woman (Gal Gadot) and Superman (Henry Cavill).

Batman takes the lead in putting together a new super-team to protect Earth. “He’s been a loner for certainly his crime-fighting career, maybe with the exception of Robin,” Snyder says. “When we meet him in BvS, he’s definitely at this low point of isolation. That was always our intention, that Justice League would be this continuation for Batman to evolve into a more complete hero.”

Wonder Woman has her own movie coming out June 2, an origin story of sorts that will “flesh out and realize (her island home) Themyscira and embrace canon with her and get all the elements to mash up that I love from the original stories,” says Snyder, who’s also a producer on Wonder Woman. “But also we’ll see that dovetail into not only the why of BvS, but even now the why of Justice League and who she is finally realized. We know now where she comes from.”

When it comes to the new guys, “they’re each such awesome personalities in the movie,” Snyder promises. “You have Jason stomping around as this inked hairy man, just this mythic figure. And you’ve got Ezra, who’s full of life and hilarious and all over the place and amazing — a really fun and also poignant Flash. And Ray’s story is in a lot of the ways the heart of the movie.”

So what about Superman, who was in a casket at the end of Dawn of Justice? “It’s hard to have a Justice League without Superman. That’s how I feel about it,” Snyder says with a laugh.

He knew BvS was going to act as a Justice League prequel, and Snyder remembers early discussions about figuring out what part the Man of Steel needs to play.

“It was always a super-intriguing concept to me to have this opportunity to have him make that sacrifice but also have him be this, in a weird sort of way, the why of Justice League: What do you do now with him? What does the team think? What does the world need?” Snyder says. “All that comes into play. It’s fun for us but it’ll be interesting for audiences what we do with him.”