It’s been 10 years since Iron Man inaugurated the era of the modern superhero movie, but in 2018, the genre entered its adolescence a few years ahead of schedule. Infinity War flirted with nihilism like a teen who’s just read his first Sartre, and Deadpool 2 tested boundaries like a kid who’s just realized she can curse in front of her parents. Venom was a mall goth, fashionably angsty but unable to hold the pose, while Ant-Man and the Wasp crouched behind the bleachers, getting high and mumbling something about the “quantum realm.”

It’s been an awkward phase but an exciting one, full of possibility and genuine strides forward. Black Panther and Spider-Man: Into the Spider-Verse broke free from the franchises that spawned them, telling largely self-contained stories and building new worlds from scratch. Now, finally, Aquaman, which arrives to close out the year, breaks new ground by leaving it: It creates an entire universe, a constellation of undersea kingdoms, each distinct from, and even wilder than, the one before.

Directed by James Wan and written by David Leslie Johnson-McGoldrick and Will Beall, Aquaman is nominally part of the DC Extended Universe. (DC’s Geoff Johns shares story credit with Beall and Wan.) But apart from a passing mention of Justice League’s big bad, you’d never know this is a world where Wonder Woman and Superman exist. When Arthur Curry (Jason Momoa) finds out that the kingdoms of the sea, home to his exiled mother, Atlanna (Nicole Kidman, playing Momoa’s mother despite the fact that she barely 12 years older), and the land, home of his lighthouse-keeper dad (Temuera Morrison), are about to go to war, he doesn’t pick up the Batphone and get a busy signal. He’s told he’s the only one who can stop the coming conflict, and though he’s reluctant to bear the burden, he never tries to shift it.

Yes, there is an octopus that plays drums. No, that is not the weirdest bit.

The Kingdom of Atlantis’ hostility to the surface world is ostensibly sparked by humans’ misuse of the sea: The opening strike, authorized by the ruthlessly ambitious King Orm (Patrick Wilson), is a series of tidal waves that returns to the land all the trash with which we have littered the ocean. But Orm’s goal is a simpler, more elemental one: power. He fakes a pre-emptive strike by a stolen submarine, commandeered by the high-tech pirate, Black Manta (Yahya Abdul-Mateen II), then uses the supposed provocation to force the other kingdoms to fall in line.

Arthur is the first-born son of Atlantis’ former queen, and therefore its rightful king. But he’s also an exile, a foreigner, and worse, at least as far as the Aryan-looking Orm is concerned, a “half-breed.” For Mera (Amber Heard), the princess who is betrothed to Orm but is secretly working against him, that makes Arthur the perfect “bridge between land and sea”—not only Atlantis’ true ruler but a chosen one who can unite the worlds. Doing so involves a prolonged quest for a sacred trident that takes him to strange terrains and the remnants of crumbled civilizations, through combats with ancient monsters, and to a final battle in which massive warships explode in slow motion as smaller craft dart through their wreckage. All of which is to say that if Aquaman is not the best comic book movie of 2018, it is at the very least the best Star Wars movie of the year.

Notwithstanding its lineage, Aquaman has more in common with fantasy film cycles than the comic book juggernauts of recent years. Momoa’s Aquaman isn’t tortured and conflicted; he’s a badass, and he digs it. He whips his long hair around like a speed-metal guitarist, but his cocky bravado is laced with just the faintest hint of overcompensation; he’s almost as great as he thinks he is. To be fair, his labors would test even the most Grecian of gods: The movie takes him from the sands of the Sahara to the rooftops of a Sicilian fishing village, and from the glowing spires of Atlantis to a deep-sea trench swarmed by spiny nightmares. Like Wonder Woman and Black Panther, Aquaman allows its makers to imagine an advanced society built on technological advances other than our own, and to do it several times over. There’s a kingdom of scaly fish-people, and another whose inhabitants look like vaguely humanoid crabs. When Mera dresses for a royal occasion, her gown’s high collar is made of luminous, floating jellyfish, and when Orm and Arthur meet in gladiatorial combat, the thundering drums that rile the crowd are played by an octopus. (Yes, there is an octopus that plays drums. No, that is not the weirdest bit.)

There are parts of Aquaman that are so wonderfully strange that it’s astonishing to see them in a franchise blockbuster. It’s like watching Jupiter Ascending or Valerian and the City of a Thousand Planets but with a full house rather than three people who have inadvertently wandered into the wrong theater. Wan not only embraces the inherent silliness of a hero whose signature power is talking to fish; he revels in it, finding the childlike awesomeness at its core. You can still see every plot beat coming from miles away, but it feels like destiny rather than repetition, the fulfillment of a promise every movie makes and few deliver on.