Cartoon Network's Adventure Time is kind of a weird show. Anyone who's watched an episode can tell you that. Explaining the show is simple enough: 12-year-old Finn, the human, and his best friend and roommate, Jake the dog, spend their time going on adventures. Together, they fight evil, rescue princesses and generally explore the surreal Land of Ooo. But there must be something special there, because the show's not only been a big hit among kids, but has been a runaway success among 20-somethings from the start, with a vast fandom online. After only a year and a half on the air, the show has been name-dropped by Tyler the Creator, nominated for two Emmys and featured both Andy Samburg and Neil Patrick Harris as guest voices. Considering it's just started its third season in July, the show has done well for itself.

While it's impossible to pin down what exactly draws so many people to Adventure Time, the setting itself is a good place to start. Ooo is a pastel-colored land where there's a kingdom populated entirely by candy people, eldritch abominations lurk in abandoned subway tunnels and the world is littered with Zelda-style dungeons waiting to be explored. It's bright and colorful enough to appeal to kids, but it has enough internal logic to keep the older crowd hooked. The surrealism of Ooo doesn't come from a series of non sequiturs like the cartoons from the 1930s. The place has rules. There are reasons why things are the way they are, and the ruined skyscrapers and bit of modern technology suggest something happened to make Ooo the way it is. This is honestly part of the fun, along with the fact that the creator, Pendleton Ward, has obviously poured his heart and soul into making this show. His childhood love of Dungeons and Dragons and videogames are evident as Finn and Jake go off on adventures. This sensibility, coupled with Ward's admitted love of writing "stupid things" are part of what make Adventure Time so much fun, and they show no signs of stopping anytime soon. Therefore, now is the perfect time for newcomers to get involved, especially since they just aired their most-talked-about episode yet, "Adventure Time with Fionna and Cake."

"Fionna and Cake" isn't really a standard episode of Adventure Time; it's actually a gender-swapped episode—meaning Finn is now Fionna, Jake the dog is Cake the cat, Princess Bubblegum is Prince Gumball (voiced by Neil Patrick Harris) and the Ice King is the Ice Queen. This episode has been the subject of a lot of hype, ever since character designer Natasha Allegri first created a one-page comic starring Fionna and Cake. From there, anticipation built as fans got more and more into fleshing out the story behind the gender swapped characters. Eventually, Allegri announced that Cartoon Network would actually make an episode out of the characters, and fans rejoiced. The writers could have coasted on the hype alone and turned this into a novelty episode, but instead they decided to make one of the smartest, most self-aware episodes of Adventure Time yet. They found a way to appease the fans who had been flooding sites like Tumblr with their versions of Fionna and Cake without alienating the younger audience who'd be wondering why Finn was suddenly a girl. The episode itself turned out to be a commentary on the very nature of being a fan and investing so much feeling into these fictional characters, while still being really funny.

The episode itself deviates pretty heavily from the Adventure Time norm, and not just because the characters are all completely different people. Instead of exploring some evil dungeon or saving partying bears from a monster's stomach, Fionna spends most of the episode trying to figure out if Gumball wants her to go to a ball with him as a friend or as his girlfriend. Again, the writers somehow made this work: In the words of episode storyboarder Rebecca Sugar, if the episode was going to be about a date, it would be one with "swords and skulls and fighting!" They gave the fans what they wanted with the romance bits, but they never lost sight of what Fionna really is: a tough, capable girl who's all about beating up evil.

This all becomes apparent in the end when Fionna, directly facing the screen, explains that she doesn't want a boyfriend. She's happy with who she is, and will know what she wants whenever it comes around. Right then, she's talking to the fans who invested so much emotion in the life of this fictional girl and her talking cat-friend. But it doesn't really shame them. Once again, Sugar explains it best when she says it's both "a jab at, but also a huge celebration of, being a fan, of allowing something completely ridiculous to make your heart tighten." She knows what that's like, and the rest of the people making Adventure Time do too, letting them make this so insightful, and, in its own weird way, almost profound.

Of course, since it is Adventure Time, the writers use the last minute or so to completely tear down any semblance of wisdom or maturity, because that's also who they are, and the fans wouldn't have it any other way.