Four seems to be the magic number. After three unsatisfactory tries at getting Marvel’s cosmic ray-enhanced superheroes on screen, Marvel Studios got it right, gorgeously produced, well cast, gracefully relegating the origin story to a few “archival” clips, and putting our quartet and us right in the middle of the action.

It is set in a fantasy version of the 1960s, inspired by the visual style, not the history or pop culture. In the first scene, Reed is looking for iodine, the painful antiseptic used for minor cuts in the 50s, and Sue Storm uses something that was not invented in our reality until the 1980s. There is a Calder mobile in their headquarters living room and the men we see in the outdoor scenes all wear hats, so handsome this movie just might bring back the fedora. The production design from “Loki’s” Kasra Farahani is dazzling and endlessly inviting, a heightened version of a mid-century concept of the future. The cerulean blue and white accents of the retro F4 uniforms designed by Alexandra Byrne (“Guardians of the Galaxy”) place us in a time and a world that is like but not the same as ours.

The Four are Reed Richards (Pedro Pascal), a brilliant scientist whose body stretches, his wife Sue (Vanessa Kirby) who has the power of invisibility, including creating invisible shields, Sue’s impetuous and very single brother Johnny (Joseph Quinn), who can burst into flames and fly, and Ben Grimm, known as The Thing (Ebon Moss-Bachrach), who looks like he is made from mountain rock and is very, very strong.

As the movie begins, the world is celebrating them as heroes and protectors. It has been four years since the space expedition exposed them to the cosmic rays, they have defeated or, in the case of the subterranean Mole Man (Paul Walter Hauser), negotiated a peace agreement, and established a United Nations-type organization called the Future Foundation.

The superheroes and the people they protect believe F4 and their adorable robot, Herbie, will always keep them safe. And then they face their biggest and most terrifying challenge. Sue is pregnant. While Reed and Sue know that the molecular changes from the cosmic rays may affect the baby, they believe, with some reassurance from Sue’s ability to make her abdomen invisible so they can see the fetus, the baby will be fine.

Big and terrifying challenge #2: the Silver Surfer (Julia Garner) arrives to announce that Earth is about to be consumed by Galactus (Ralph Ineson), a planet devourer. F4 tracks the Silver Surfer to find Galactus, confident they can defeat him. And this leads to the first Marvel action sequence that features a very pregnant superhero. Galactus offers them a terrible choice, and when they refuse, the people on earth quickly go from fans to haters.

The film moves briskly, with one of the shortest run times in the MCU, under two hours. But it creates a fully-realized world, with small details like the Mole Man’s dad jokes, Ben Grimm’s “beard” and copy of 50s classic child care bible Dr. Spock, and a sweet brief appearance by Natasha Lyonne as the teacher of students who are big fans of The Thing. Fans will enjoy some glimpses of popular villains from the comic books. Director Matt Shakman (the similarly retro fantasies “Game of Thrones” and “Wandavision” and “The Great”) understands that the action scenes and the family dynamic are central to the storyline and he has fun with scale when Galactus arrives. While the stakes are dire, he stays away from gratuitous carnage. The film has good-natured humor, impressive special effects, some tender moments, and even a light gloss of commentary on what we expect from our heroes, and how we approach moral dilemmas and life-threatening challenges. I’m iffy about one twist, but overall, this is a film that respects comic book characters and what we love about them.

Parents should know that this movie features extended comic book/action-style peril and violence, with some scary creatures and disturbing and graphic images. There are mild references to reproductive biology and a woman goes into labor (discreetly filmed). Characters use some mild language.

Family discussion: Philosopher Jeremy Bentham argued that all decisions should be based on the greatest good for the largest number of people. How does that idea appear in this film and do you agree? What do you think will happen to Franklin? What is the law of levers and how do you see it around you?

If you like this, try: “Superman,” The Fantastic Four comics, and maybe just for fun watch the earlier films so you can compare them.

NOTE: Stay through the credits for one extra scene indicating where the story is going and, at the very end, a nostalgic moment.