They’re here.

Steven Spielberg premiered a new trailer at CinemaCon on Wednesday for “Disclosure Day,” his return to summer blockbuster filmmaking after a decade mostly spent making personal dramas (“The Fabelmans”) and prestige fare (“West Side Story”). The film’s plot has been shrouded in secrecy, but it involves visitors from another planet and a vast government conspiracy to cover up their arrival. It’s a genre that has been good to Spielberg over the years, inspiring classics such as “E.T. the Extra-Terrestrial,” “Close Encounters of the Third Kind” and hits like his remake of “War of the Worlds.”

Here he’s supported by a starry cast that includes Emily Blunt as a weather reporter with a connection to otherworldly visitors; Josh O’Connor as a man with evidence that we’ve made contact; and Colin Firth as a nefarious bureaucrat who will stop at nothing to keep our heroes from going public. Eve Hewson and Colman Domingo round out the ensemble. David Koepp, who penned “Jurassic Park,” wrote the script. Spielberg called the sci-fi premise “closer to truth” than you might think.

“I’ve been curious ever since I was a little kid with what was happening in the night sky,” Spielberg said.

He noted that there has been increasing evidence that unidentified flying objects are real, referencing a 2017 report in the New York Times on a secret Pentagon program to investigate these mysterious sightings.

“The world became more accepting of the fact that we probably are not alone,” Spielberg said. The director’s certainty that intelligent life is out there has only grown in the nearly 50 years between the release of “Close Encounters of the Third Kind” and “Disclosure Day.”

“I believe this movie is going to answer questions and this movie is going to cause a lot of people to ask a lot of questions,” Spielberg said. “All you need to get from beginning to end is a seat belt,” he added.

There was lots of that Spielbergian sweep on display in the footage that he presented on Wednesday. Blunt and O’Connor crash through a farm house while evading government agents and later climb onto a speeding train. As for the aliens, they are glimpsed fleetingly. A ship (is it a flying saucer?) starts to materialize out of an ink-black sky; a hand that is definitely not human reaches up to caress a face. But do they come in peace?

At CinemaCon, Motion Picture Association CEO Charlie Rivkin presented a visibly emotional Spielberg with a “one-time honor, the America 250 award,” which was followed by a conversation between Domingo and his “Disclosure Day” director. It marks Spielberg’s first visit to the exhibition industry trade show.

“I promise you this will not be my last,” Spielberg promised after receiving a standing ovation.

Spielberg wasn’t just in promotional mode. He came with advice about how to sustain an art form he loves. That started with a plea to keep movies in theaters longer before debuting them on home entertainment platforms. To that end, he praised Universal, the studio behind “Disclosure Day,” for its recent decision to increase the number of days its films are in cinemas from as few as 17 to 45.

“Audiences will find what they want to watch, whether the films are big or small, but studios need to help us by greatly expanding the exclusive windows like [Universal Entertainment chief] Donna Langley just did,” Spielberg said to loud applause. “Today I’ve got to be greedy. Do I hear 60 days? Do I hear 120 days?”

Spielberg stressed that studios like Universal need to keep investing in original films like “Disclosure Day” instead of reboots, sequels and spinoffs.

“If all we make is known, branded IP, we’re going to run out of gas,” Spielberg said. “There is nothing more important than giving the audience visual stories, and they can be in any form, but we need to tell more original stories.”

But will “Disclosure Day” prove that audiences want something new and different or will it struggle to draw crowds to a movie that isn’t based on a comic book or a video game? We’ll find out if Spielberg is right when it opens on June 12.