This review contains spoilers for episode 7 of What If...?.

Marvel’s What If...? has arrived at another one of its most highly anticipated storylines. After turning T’Challa into Star-Lord in the second episode and turning the Avengers into zombies in the fifth episode, the What If...? writers have finally introduced “Party Thor” in the seventh.

“What If... Thor Were an Only Child?” takes place in a universe where Odin returned Loki to the Frost Giants instead of raising him as his own son. So, Thor grew up without a sibling rivalry to inspire him to become a hero, and as a result, he’s even more arrogant and entitled than he was at the beginning of his first solo movie. Instead of coming to Earth to earn back his powers and save humanity from the Destroyer, the God of Thunder comes to Earth to throw an epic party in Vegas on the down low (because Midgard is largely ignored by Asgardians).

RELATED: What If...? Mid-Season Trailer Hints At A Big Multiverse Team Up

Since the last few episodes have explored dark alternate scenarios that would doom the world of the MCU, it was a nice change to shake things up with a lighthearted comedic story. After What If...? has explored such new genre frameworks as murder mysteries and zombie movies, “What If... Thor Were an Only Child?” offers the MCU’s first raunchy hangout movie in the mold of Dazed and Confused or Project X, but with hard-drinking alien superheroes instead of hard-drinking high schoolers.

Party Thor in Marvel's What If

For once, “What If... Thor Were an Only Child?” has all the right voices. Most What If...? episodes have featured a mix of familiar voices from the big screen and relative impostors who don’t sound quite right. In the latest episode, Captain Marvel is played by a returning Alexandra Daniels, but aside from that, Chris Hemsworth plays Thor, Natalie Portman plays Jane Foster, Kat Dennings plays Darcy Lewis, Cobie Smulders plays Maria Hill, and Jeff Goldblum plays the Grandmaster. It seems silly, but the characters sounding right goes a long way.

“What If... Thor Were an Only Child?” seizes What If...?’s unique opportunity to have superheroes fight each other and see who would win without having to tear apart the mainline continuity like the superhero-on-superhero fights of Civil War. Thor’s fight with Captain Marvel in this episode is more thrilling and engaging than the titular scuffle in Batman v Superman. There’s one particularly cinematic moment that the animators used to play around with light: the two squabbling superhumans go through a dark cloud with the action illuminated by the Tesseract energy in Carol’s eyes and the thunderbolts blasting out of Thor’s hammer.

Thor hanging out with Skrulls in Marvel's What If

In addition to interesting lighting, which has been a positive quality of every What If...? episode so far, “What If... Thor Were an Only Child?” also has fun with the editing. There are a couple of great gags that draw humor from back-and-forth cutting: cutting between Thor and Loki wishing upon what they think is a shooting star and Captain Marvel hurtling toward them to fight; and cutting between Frigga racing to Earth and Thor desperately trying to scrub his “THOR ROCKS” graffiti off the wall of the Leaning Tower of Pisa (which now stands upright after he gave it a little nudge). The MCU usually gets laughs entirely from quips and one-liners, but these visual flourishes in What If...? offer a different kind of comedy.

The episode culminates in a hilarious climax as S.H.I.E.L.D. resorts to calling Thor’s mother to put an end to the party. MCU stories usually come to a head with big battle sequences with world-ending stakes, but this one ends with a god afraid of disappointing his mom desperately cleaning up after a worldwide rager. Ultimately, this episode’s underlying message is that Thor’s feelings for Jane are so strong, he was going to fall in love with her no matter what. This was a better love story than any of the romantic subplots in the Thor movies.

Ultron emerges from a portal in Marvel's What If

The only thing that doesn’t work in this episode is its final scene, whose shock factor feels forced. An Infinity Stone-powered Vision/Ultron hybrid emerges from a portal with robotic henchmen, possibly setting up a future episode, but it’s so arbitrary and out-of-the-blue that the weight of the situation doesn’t land. What If...? has had a lot of endings like this that resolve the narrative at hand (like revealing who’s been killing Earth’s mightiest heroes), then throw in a random left turn (like Loki taking over Midgard) just to take advantage of What If...?’s unique position to give a Marvel story an unhappy ending. Sometimes, it works – like undead Thanos having invaded Wakanda at the end of “What If... Zombies?!” – but most of the time, it doesn’t. A multiversal Ultron suddenly arriving at the end of an episode about partying felt completely inorganic.

On the whole, though, “What If... Thor Were an Only Child?” is a lot of fun. Its overtly comedic tone was a refreshing change of pace after the last few bleak episodes, and it did a better job of creating a tangible romance between Thor and Jane than the actual Thor movies did with several more hours of screen time.

MORE: What If...?'s Zombie Captain America Gets A Live-Action Makeover In This Impressive Fan Art