When we talk about TV shows, we have a nasty habit of using "soap opera" as a pejorative, a shorthand that lets us belittle the twists and turns on Mad Men or Scandal. But soap operas were the first format to introduce long-term seriality to television; if you enjoy Breaking Bad or The Americans, you have soaps to thank. And if you were ever a sucker for Degrassi or Pretty Little Liars or pretty much anything on the CW, that's because the emotional intrigue inherent to soaps makes it a natural fit for those ever-melodramatic teens. The writers of Adventure Time on the Cartoon Network clearly know all this already, because tonight's episode, “The Diary,” takes on all of the conventions that make soap (and teen soap in particular) not only fun, but an integral and longstanding part of the TV landscape—a practice they’ve engaged in time and time again with other genres, allowing Adventure Time to grow into the sprawling, mind-bending series it is today.

[Warning: numerous plot points for tonight's episode follow.]

TV, Jake the Dog’s son, takes a break from his video game obsession when he happens upon the discarded diary of a teenaged girl known only as “BP,” which engrosses him so much that he begins to think as her in an effort to puzzle out her identity. The diary, which chronicles the conclusion of BP’s tumultuous relationship with a boy named Justin, features intrigue, deep insecurity, and of course cool records bootlegged from Lumpy Space—but it's missing pages describing BP and Justin’s romance reaching its boiling point. What happens? This structure allows writer and storyboard artist Jillian Tamaki to effectively build an Adventure Time quest out of an afterschool drama—the only way the show could be any closer to doing a full-on Degrassi episode would be if the producers got Drake to do a guest spot.

While there's an immediate thrill in seeing Adventure Time’s take on yet another televised genre (the way “Candy Streets” is an homage to cop shows and “BMO Noire” nods to, well, noir), it helps that TV (the character) is voiced by one of the best angsty teenagers of all time: Dan Mintz, a.k.a. Tina Belcher on Bob's Burgers. Mintz brings immediate credibility to the story, and to TV’s channeling of BP’s boy problems, in a nifty bit of intertextual casting. Even better, the casting manages to involve Jake in the diary hunt; indeed, much of the episode's humor (and quality) hinges on how excited an adult gets about the prospect of delving into some juicy high school drama.

The father-son bonding between Jake and TV is also a stealthy way of treating one of this season’s biggest themes: parenting. Finn’s father, Martin, has returned to his son’s life and repeatedly proven to be a big jerk, shattering Finn's illusions to the point of resignation; meanwhile, one of Jake’s other sons, Kim Kil Whan, has grown into a slick businessman, bemoaning his father’s irresponsible, immature lifestyle like a canine Alex P. Keaton. While most of this season has presented poor parenting, Jake seems to be acting in TV’s best interest in "The Diary," trying his best to get his son to invest in something.

But Jake’s plan wouldn’t work if BP weren’t such a compelling character, enmeshed within a web of classic teen drama. She has universally relatable problems, and in that sense is a classic teen-show everygirl. Yet the intimacy provided by her diary makes her specifically likeable, particularly through the drawings and specialized fonts that appear on the screen as TV consumes them. That we come to care about her, even in a few short minutes, is crucial to the success of the episode—otherwise, we would have little reason to invest in TV’s quest. Likewise, the strength of any individual character is crucial to the success of the soap—when anyone on, say, Dawson’s Creek encounters an obstacle, it’s important that we actually want them to overcome it. If not, why watch?

And, just like any long-running soap (or any long-running show, really), “The Diary” proves that the journey is the important thing. In the end, BP (who turns out to be Nurse Poundcake) actually acknowledges that she and Justin would never have worked as a couple. And accordingly, TV doesn’t care about finding Justin. He doesn’t even give Nurse Poundcake the music box Justin had left for her years before. What would be the point? The whole episode is about TV and Jake spending some father-son time together while we, the viewer, get to know what Adventure Time’s version of the teen drama is.

“The Diary” makes a serious argument in favor of the teen soap: it’s fun, emotionally engrossing, and legitimately exciting to get sucked in by the imagination of a kid. (This argument may be true, but it’s not subtle; TV literally goes on an emotional roller coaster while imagining BP’s life.) That’s exactly what Adventure Time is in the first place: a magical journey through childhood, with elaborate conflicts and battles. TV gets pulled in by the power of a story, and rather than having his brain rotted, he manages to employ not just deductive skills, but also something that might be called empathy.

In the past year or so, the mythology of Adventure Time’s Land of Ooo has become increasingly elaborate, with a number of separate stories playing out in parallel—from the adrift Lemongrab and Ancient Psychic Tandem War Elephant to Betty’s attempt to save the Ice King. Each of tales are Trojan horses that smuggle larger issues into viewers’ brains—growing up, relating to one’s parents, or just trying to be a good person. It’s a marvelous achievement of storytelling, and a testament to the powers of the Adventure Time team that any given episode can check in on Cinnamon Bun and Flame Princess, Tree Trunks and Mr. Pig’s Lich baby, or even, in the case of last week’s episode, Susan Strong—a character who hadn’t appeared since Season One—and produce something compelling that also has ramifications for the rest of the show’s world.

With that in mind, the simple existence of Adventure Time in its current, dizzying form is perhaps the best case in recent memory or us all to stop making fun of soaps (well, besides Empire). Each time AT transcends its “boy hero and talking dog fight monsters” premise, whether by digging into the lives of peripheral characters or simply becoming a different kind of show, it not only acknowledges that Ooo is complex enough to contain many different kinds of stories, but it helps further strengthen the connections between disparate corners of its fantastic world. So “The Diary” manages to be an 11-minute argument for the continued relevance of a disrespected genre. But that shouldn’t stop anyone from enjoying it on its own terms—the genre may be crucial to the development of world-building TV shows, but if the comedy of “The Diary” is any indication, soap is also great at giving us good, clean fun.