I love alternate-universe superhero comics, be they What If?s at Marvel or Elseworlds over at its Distinguished Competition. At their best, they can tell compelling stories outside of the all-important canon while still offering an example of why that canon is so all-important. You get to see what would happen if Spider-Man were the Punisher and also if he had the Venom symbiote, which sure sounds fun, but you also get to see why it wouldn’t work if Spider-Man was always the Punisher and always had the Venom symbiote. The basic premise of the concept is that you tweak one thing from an established storyline and pull on that thread to see how it would change everything else. Marvel succinctly frames these stories as, say, “What If Gwen Stacy Had Lived?” in the comics, and the TV show does something similar with the Marvel Cinematic Universe.

It’s a good sign, then, that the first episode of Marvel’s What If…? on Disney+ actually manages to include pretty much every thing I like to see in an alternate-universe superhero story, meaning it’s a fantastic example of the ideal version of what this show could or should be in my mind. The premiere has someone new taking on the mantle of an iconic hero, winky jokes about the regular timeline, and ends in such a way that hints at where this particular timeline could go by teasing a reality that is arguably cooler than the one shown in the actual MCU. It notably stumbles into a mistake that always irks me in alternate-universe stories like this, but aside from that, it’s just an absolute blast.

The What If…? this time around, as nicely laid out by Jeffrey Wright’s The Watcher (who narrates the beginning and end of each episode and will never, ever, ever interfere in what happens in them, unless he ends up doing it all the time like The Watcher does in the comics), is that Peggy Carter ends up getting the super soldier serum instead of Steve Rogers—who actually gets shot, severely injuring him and making it difficult for him to walk. Unlike Steve’s Captain America in the movies, who was happy to make pro-America propaganda for a while before realizing he could do more as an actual super-soldier, Peggy is immediately and immensely frustrated with the misogynistic military men who refuse to entertain the concept of a woman going to the frontlines and righteously slaughtering Nazis.

Luckily, Howard Stark is happy to throw together a Union Jack-themed costume and shield for the newly dubbed Captain Carter, who promptly goes off to righteously slaughter some Nazis and—in a major diversion from Captain America: The First Avenger—recover the Tesseract before the Red Skull even gets his fascist hands on it. That gives Howard an opportunity to create a brand new piece of Hydra-stomping tech: the Hydra Stomper… which is just a WWII Iron Man suit. Little Steve Rogers uses the suit rather than Howard himself, but much like in the many alternate-universe Batman stories where Bruce Wayne’s dad is the Dark Knight, some superhero gimmicks are genetic.

From that point on it’s just a straight-up action romp, with Peggy going on to rescue Bucky Barnes (who notably does not fall off the train here, though he does make a joke about how dangerous it is and how he could lose an arm) and then her and little Iron Man Steve Rogers trash the bad guys in a series of excellent action scenes. There’s a great mid-air sequence with Peggy jumping from plane to plane and beating up everyone inside, and an attack on a Hydra base where the camera flips and spins to follow Peggy’s movements that has more visual panache than pretty much anything in any of the live-action MCU adventures.

Plus, in what little downtime there is, Peggy and Steve make repeated references to someday being able to “dance” with each other (wink, wink, just like in the movie), and there’s a very sweet moment where she tells Steve that he’s her hero because of the way he keeps fighting even though he’s a little guy, and then he responds by saying that she’s his hero. As an enormous fan of Steve/Peggy’s romance in the movies, I absolutely love this stuff. It’s a deepening of their relationship in a way that there wasn’t really time for before, and it shows just how much potential for good stories there is in this concept—beyond, you know, how awesome it is to see Peggy Carter beating the shit out of Nazis.

But, unfortunately, there is that aforementioned stumble. Hold on while I get real nerdy with this: In Captain America: The First Avenger, the Tesseract that the Red Skull initially finds in the church is a fake, and the real one is hidden nearby. In this episode, (and maybe this is just me missing it) the sequence of events regarding the fake Tesseract isn’t totally clear, so it seems like the Red Skull doesn’t actually find the real one until the end of the episode when he uses it to summon a tentacled space monster—meaning the one that Peggy swiped early on was the fake.

This is what bugs me: In the movie, Red Skull destroys the fake cube because he knows it’s fake, and then he gets the real one right after. If that’s not exactly how it happened in this What If...? reality, and it doesn’t seem to be, then it cheats the basic concept by altering two unrelated things about the original universe. Everything has to spiral out from Peggy getting the serum instead of Steve, or else this becomes “What if Peggy replaced Captain America and also the Red Skull didn’t find the real Tesseract until later?”

That’s just a little sticking point in an episode that is otherwise a ton of fun, and given the way it ends—with Peggy getting sucked into a portal in the 1940s and then reappearing in the S.H.I.E.L.D. base in The Avengers—is a great hook for hypothetical follow-up adventures… except they’re not hypothetical. The creators of the show have already teased that they’re working on another season, and Captain Carter is the one character they’ll admit to bringing back next time around. I, for one, could not be happier about that. Let’s hear it for Captain Carter.

• What’s the What If? What if… the crowd watching Steve Rogers get the super soldier serum had stayed in the room?
• Did they cheat? A little bit, with the Red Skull apparently having the real Tesseract the whole time.
• Did The Watcher interfere, even though that’s the one thing he must never, ever do? Nope! Good on you, Watcher.
• Seriously, I cannot overstate how much I loved that mid-air sequence. That’s the kind of scene that animation was made for, and I’m so happy to see this show doing stuff like that rather than just attempting to replicate a live-action movie.
• Sometimes you have to come up with a superhero name, and British intelligence agent Peggy Carter deciding that the American military should just start calling her “Captain Carter” is some efficient streamlining. (Captain America got the name from his propaganda movies and also may not actually be a captain.)
• In what I suspect is going to be A Thing going forward, Disney did not release the official cast list for this episode ahead of time, and the credits were blacked out on my screener. It’s obviously Hayley Atwell doing a great job as Peggy and Bradley Whitford as the military jerk who is not Tommy Lee Jones’ military jerk, but everyone else (some of whom are from the movies) is mostly just fine. Teaser: We’ll have more reasons to talk about voice acting next week.