Writing about the NBC show Community, a sitcom set in a studiously unstudious community college, is difficult. The show is so self-referential that it has already discussed itself comprehensively. Recently in Slate, I referred in passing to an elaborate, mind-bending episode, “Paradigms of Human Memory.”Community isn’t a high-cost or highly rated show, and it couldn’t have been easy for the producers to put together such a dense and multilayered 22 minutes. “Paradigms” is being rerun this week. In its honor, let’s attempt to unpack what might be the most complex sitcom episode ever filmed.

One way for a series without a big budget to do a big-budget show is to save money (and time) by doing other shows in the season cheaply. This is known in the business as doing a “bottle episode” (like the famous Seinfeld one set in the lobby of a Chinese restaurant). If you can stick your cast in one room (the “bottle”) on a contrived plot pretext, you can economize by doing a continuous shoot with no scene changes, extras, or guest stars. I know about bottle episodes only because Community did one earlier this season, in a show called “Cooperative Calligraphy.” A cute young student named Annie loses one of her pens in the study room and demands its return. The show, in typical self-referential fashion, makes an issue out of whether everyone should stay in the room and thus make the episode a “bottle episode.” (The lameness of the pretext was part of the joke.)

Now, as I said, the “Paradigms” episode of Community becomes spectacularly ornate. And the concept of the bottle episode resonates within it in two ways. For the first, “Paradigms” patterns itself carefully after that earlier episode. “Calligraphy” is mentioned immediately in “Paradigms,” and it’s referenced so many other ways that it’s obvious the producers meant for the episodes to be parallel. Secondly, “Paradigms,” it turns out, is a bottle episode itself, after a fashion. It also takes place in the study room with no outside characters. All the craziness (and all the expense) technically takes place in the characters’ minds, as they discuss their memories of their time together. These memories, whether reliable or not, bury the potential bottle episode in a flood of expensive outside sets and ever-more-baroque set-ups. The relationship between the two episodes is just one little example of how wound up this show is. Community isn’t just self-referential. Self-referentiality is its raison d’être.

If you haven’t seen Community yet, here’s the background: The setting is a study group at the blissfully mediocre Greendale Community College, a melting pot for just about everything—class, age, race—except an ability to function well in society, and perhaps intelligence. At Greendale, even the smart people are dumb enough to be going there. The show’s creator, Dan Harmon, a smart guy who was the head writer on The Sarah Silverman Show, came up with the idea after taking a Spanish class at an L.A.-area community college.

Our protagonists number seven, with a deliberately clichéd diversity: a young black guy, Troy, who is pretty dense, and best—almost too best—friends with Abed. A slightly older black woman, Shirley, who is a guilt-tripping Christian, no-nonsense single mom. An older white guy, Pierce, played by Chevy Chase, moneyed but a dolt. A younger white guy, Jeff, the group’s acknowledged leader, disgraced lawyer, full-time sophist, and pretty boy, played by Joel McHale. A Muslim guy, Abed, half-Palestinian, half-Polish—more on him in a bit. A comely young white woman, Britta, high-strung and stupidly P.C., and an even comelier young white woman, Annie, a former drug addict and the woman who lost her pen.

Outside of ongoing jokes about the school’s academic haplessness, the show isn’t about education, and I don’t read it as a stand-in for America. Rather, the show is about itself in particular and TV in general, but again with a sort of blank aimlessness that often produces a vortex of jokes about some marginal bit of pop culture, like the rock group Barenaked Ladies, who are debated at length in the context of whether they are worthy of being debated about at all. Leaving aside a few fantasy-type sequences, the action of the show takes place in the study room and some classrooms or public facilities around the school, and the plots are generally intensely insular, to the point where at least one episode seems to have occurred largely in one character’s head.

And that would be the head of our thematic host, the half-Palestinian guy, Abed, who has a marked case of Aspergers but boasts an encyclopedic set of pop-culture referentials, most of them of middling quality (he has a Batteries Not Included poster on his dorm wall), which he shares with the rest of his cast and us, the viewers, in order to chart the show’s homages to TV shows and movies.

Since the demands of the American sitcom are that a group of friends encounter problems that test their relationships and get resolved 22 minutes later, this is what generally happens here, but with self-consciousness and, importantly, an accompanying sourness. McHale’s character, particularly, is a moral black hole whose unattractiveness is only slightly relieved at the tidy wrap-ups that some episodes sport.

Here’s a typical exchange:

Troy: “Jeff, what do you do when you and your best friend want to ask the same girl to the Valentine’s Dance but neither of you have dibs because you both fell in love with her at first sight?”

Jeff: “Well, I don’t believe in dibs, or love at first sight, or love, or best friends, or doing things. But it’s good you brought this to me.”

Since it’s a sitcom about sitcoms, the romantic opportunities available are picked at like scabs. The series begins when Jeff tried to make moves on Britta by concocting a imaginary Spanish study group. Britta sees through the ruse easily, creating a distance between her and Jeff. Since the two are the most conventionally attractive, they are by TV standards destined to hook up, a prerogative the rest of the group grumpily acknowledges. This initial iciness delays the coupling, but Abed’s pop-culture antennae measure the pair’s varying distance precisely on an ongoing basis.

When it’s revealed Jeff has kissed the very young Annie, it produces a remarkably feel-bad episode. Then there’s a despised Spanish teacher named Chang, who after a fall from grace is now a student and a pathetic group hanger-on. His hook-up with Shirley, an emotionally and physically formidable mother of two, is treated by everyone concerned, with the exception of Chang himself, as an unappetizing liaison.

So Community is not without some conventional constructions. On top of these the writers dance like Fred Astaire. An early episode found the group taking control of the school cafeteria in a Goodfellas parody. A Christmas fantasy last year had the group go through its motions in Claymation, all taking place inside Abed’s head. Once each season, there’s a massive school-wide paintball fight. The first one genuflects toward latter-day horror films like 28 Days Later (along with, of course, a dozen other movies). The one this year, a two-parter that ended the season, begins as a spaghetti Western, but changes in the second episode, when Abed announces that it will continue as a Star Wars homage. The women in the crowd moan. “I know, I wish it had happened sooner, too,” Abed says.

Some of the pop-culture references are almost indigestible, and delineating them can be more trouble than it’s worth. Take, for example, the school’s dean, a barely closeted compulsive cross-dresser whose pathologies, including a fixation with Jeff and an active participation in the local plushie scene, are on prominent, discomfiting display. At a Halloween party, Britta tells him that his iPod, which is providing the music, is also playing private “note to self” audio messages. We hear, “Check Netflix for that movie where Greg Kinnear is a ghost. No, an angel. And something called Human Centip-…”

This is a bit hard to parse. The Kinnear slam seems just to be a blank reference to the Ricky Gervais film Ghost Town, in which Kinnear co-starred, but the joke could be that he’s confusing Kinnear and Patrick Swayze, who was in Ghost. Then comes a hugely gratuitous reference to a reputedly revolting torture-porn film called The Human Centipede. I won’t gross you out with the details, which have captivated some writers and provided fodder for South Park’s truly foul season premiere a few months ago. Here, the joke seems to be that the dean had heard about the film second- or third-hand and had no idea what he was in for.

But as the second season has trundled along, some of the conceptions have taken on a virtuosic quality. In one of them, Jeff works hard to put together a surprise Pulp Fiction theme party for Abed’s birthday, with the various members of the cast dressed up as characters from that film. (Shirley is given Samuel L. Jackson-like whiskers.) But Abed just wants Jeff to take him out to dinner at a nice restaurant and, uncharacteristically for someone with his affliction, have a normal, deep conversation. The episode is two-thirds over before we realize what’s going on. Abed has obsessively created his own My Dinner With Andre-themed episode even as Jeff was trying to pull off the Pulp Fiction homage. In the process he infuriates Jeff, who realizes that the human connection he’d been making with Abed over the meal was false. Live by the homage, die by it.

* * *

Anyway, even by Community standards, “Paradigms of Human Memory” is an extreme example. If you haven’t seen it you can stop reading here.

It begins with the group looking at a diorama they’ve just completed. (Dioramas are one of the show’s academic punchlines.) It’s their 20th diorama together, and it portrays … the group making its 19th diorama together.

That thematic fanfare tells us the show is going to be even more self-conscious than usual. Indeed: A monkey comes into the room, steals a spoon, and runs into an AC vent. We remember the monkey from “Calligraphy”; we know that it had stolen Annie’s pen, too. (The monkey belongs to Troy and is named “Annie’s Boobs,” incidentally.) Chang strips down, unappetizingly (and unnecessarily) coats himself with Vaseline, and follows the monkey into the duct to investigate. He finds a storehouse of objects the creature had stolen from the group, which, once recovered, are used so the characters can reminisce about their past together, starting with Annie’s pens.

So now the show has announced its intentions, and, as I noted above, made its connection to the bottle episode clear. Next comes a reminder of how bruised the group’s relationships are. It doesn’t take long for Abed to sense that Jeff and Britta have been hooking up without telling the group. We see a brief flurry of flashbacks that establish the affair, but also sense something off about the flashbacks. They are not scenes from the actual show, but rather, outtakes from previous episodes. That’s fair, and to viewers they “read” as part of the possible narratives. But one makes a reference to an “exciting St. Patrick’s Day episode” in which we see Abed in an orange life vest and a green St. Patrick’s day bowler. Now, I knew that show had never been aired, but the episode kept moving and I didn’t have time to process what it meant.

Indeed, the revelation that Jeff and Britta had been secretly boffing creates a general sense of outrage and sets a tone of discord among the characters that will persist through the rest of the episode. The group then starts remembering different ways they’d all been mean to each other, with a dozen more flashbacks piling up, some of them creating the same feeling of offness that the St. Patrick’s reference did.

Then someone picks up a sheriff’s badge, and Jeff takes the show down a rabbit hole.

“Oh, the deputy’s badge from when we spent the day in that old ghost town,” he says. This is a key moment, because we’re sure the group never did spend a day in a ghost town in any of the previous episodes, and it didn’t plausibly happen in any case. But we then see Abed and Troy chased out of a saloon by a crotchety Western character-actor-type firing a shotgun at them. “That was one of the best days of the whole year, and I almost totally forgot about it,” Jeff marvels. Here and throughout the episode at such moments, a few other characters say, “Oh, right,” but their tone is somewhat tentative; their confidence in the existence of the memory seems doubtful.

The rest of the show is based on a slow trickle and then a full firehose of such scenes, some of them, again, “real”—i.e., scenes we’ve seen or scenes that seem to be legitimate outtakes from previous episodes—but most of them patently absurd, like one that finds the group being held at gunpoint by South American drug lords. By the end of the show, the scenes flit by at a rapid clip, all culminating in a rambling and then dissociative monologue from Jeff patterned over an ultimately dizzying series of rococo scenes.

The first time you see the episode it’s hard to take in; the second time you try to figure out how much work went into it. Each scene, remember, had to be conceived, budgeted, built, staged, costumed, and filmed, just for a few seconds of airtime, in addition to the two or three dozen other brief flashback scenes that were staged in the show’s regular sets but still needed to be written and filmed.

I counted more than a half-dozen full outside sets the show had to work on, and another half-dozen or more smaller scenes outside the show’s normal bailiwick. There’s a camping trip; a visit to a cobweb-covered and seemingly haunted Civil War-era house; the Western set; the scene with the drug lords; an old timey train station; a hotel on the steps of which the group, half-undressed, is apparently trying to rid itself of bed bugs; and more.

None of it really makes any sense, perhaps because TV doesn’t make any sense. “This engine runs on us,” says Jeff in one scene, standing next to a steam engine in an old-fashioned engineer’s outfit.

Along the way there are a couple of broadsides at contemporary bits of pop culture. The cruelest is a rip on Glee, when the group remembers having been in the glee club and winning some medals. (For this the show uses yet another set and even wrote a contemptuously nonsensical song.) Annie reminds them that’s it’s not a fond memory—they’d filled in for the glee club only after it had died en masse in a bus crash. “I was remembering around that part,” Jeff says.

In another, Abed appears in the guise of the character the Cape, from a short-lived and utterly preposterous NBC series about a soi-disant superhero who uses his cape as a whiplike weapon. In one quick flashback, Abed sneaks up on Jeff in the lunchroom, obliterates his lunch with the cape, and then runs off. “That show’s gonna last three weeks,” Jeff angrily hollers after him, with retrospective prescience.

I’d like to note here that all of things I’ve been talking about occur in a single episode of a U.S. situation comedy running about 22 minutes.

Now, the big theme of this episode eludes me. Sure, memory is discussed, commented on, interpreted and misinterpreted. (There’s even an extended sequence I haven’t mentioned, whereby yet another group of a half-dozen flashbacks are shown, these being just some innocuous situations that are played and then replayed in slow motion with a romantic song in the background, allowing the characters to fight over their meaning. But of course they aren’t really about memory; they are about the choices made by a producer and director on how to use production techniques to tell the story they wish to tell, their characters’ inclinations be damned.)

Still, it doesn’t really have anything to say about memory, unless “Paradigms” is actually a spirited but somewhat wistful homage to the thoughts and ideas and memories of the characters of TV shows, which are all of course imaginary. If Philip K. Dick had written “Paradigms,” he might have called it, “Do Sitcoms Dream of Electric Shticks?”

But in the event, the group, spurred on by the revelation about Jeff and Britta, remembers a lot of fighting and carping. It climaxes with Troy, like a child dismayed at his parents’ constant sniping, having a fit about the debilitating negativity. Jeff eventually goes into one of his monologues to try to soothe the group, but this one is chopped up and spit back out again by all the flashbacks.

What we’re left with is … a brilliantly conceived show about nothing, really, other than how brilliant its conception is. If anything, “Paradigms of Human Memory” is about overkill. Flashbacks have been a droll staple of fast-moving shows like ArrestedDevelopment and 30 Rock. Here the flashbacks come in packs. There’s never just one; there are four, five, six, often ramping up to some absurdity—a cardboard robot creating panic in the halls of the school—and then deflating down to something nonsensical, like the characters all beaming as they participate in a jump-rope class. This happens over and over again. When the dean comes in dressed as a Carnival dancer, Jeff asks him how many excuses he needs to dress up in dumb costumes. The answer, as we see from an ensuing series of shots (Tina Turner, Julius Caesar, Scarlett O’Hara …) is at least a half dozen. The Cape comes back two or three more times. That’s what I meant above when I said Community already comments on itself comprehensively. “Paradigms” knows how complex it is. It’s about its own complexity.

Jeff’s summation: “So maybe we are caught in an endless cycle of screw-ups and a lot of hurt feelings, but I choose to think it’s just the universe’s way of molding us into some sort of supergroup.” But a supergroup they definitely are not. A deflating reference to the Traveling Wilburys follows, and, for now, the group’s anger is cooled, and they give a pass to Jeff and Britt’s liaison, after which the pair quickly realize that secret sex that isn’t a secret isn’t very appetizing. Then Chang comes back to take his rightful place in the universe—trapped in an AC duct and being beaten over the head continuously by the monkey. We see his figurine placed solidly outside the diorama, looking in.

You can reflect that Jeff, Abed, Britta, and the rest are just caught in their character straightjackets, trapped in the rubber room that is the conventions of the contemporary American sitcom. But that, too, was one of the recurring flashback scenes in the show. You could go further and say that, in “Paradigms of Human Memory,” Community has just taken everything that has ever happened on the show and shoved it up its own ass. The fact that that’s just a line from the same show doesn’t make it any less true. But finally, it’s also true that, in its own twisted, self-referential, postmodern head-up-its-own-ass way, the episode does with an almost giddy profundity encompass multitudes, if multitudes can be understood to include television tropes, forgotten pop culture, and plushie jokes. What show on TV is as blithely, pointlessly ambitious?