Dennis: You know what you can't do when you get the flu?
Mac, Dee, Charlie: Sing.
The gang decides to quarantine themselves inside the bar after learning of a severe flu epidemic sweeping Philadelphia. While Dennis, Dee, Mac and Charlie pass the time practicing their a cappella routine for an upcoming contest hosted by Philadelphia supergroup Boyz II Men, Frank becomes increasingly paranoid about getting sick and goes to extreme lengths to make the bar "pure".
This episode provides examples of the following tropes:
- The Alcoholic: The gang minus Frank all come to the realization that they're alcoholics once they start drinking again and suddenly recover from their symptoms. Turns out they never had the flu to begin with — they were just all in withdrawal.
- Ambiguously Gay: When Dennis claims that he can make his penis go from flaccid to erect at will, Mac excitedly states that he's seen it, earning himself weird looks from Charlie and Dee.Charlie: You gotta ease up on talking about dicks, man. Like, it's just, it's too much at this point.
- Bottle Episode: Most of the episode takes place inside the bar and only involves the principal cast.
- Bubble Boy: Charlie apparently never got the flu as a child since Mrs. Kelly made him wear a bubble boy suit every year during flu season. Both he and Mac later end up wearing them during a trip to the convenience store.
- Captain Obvious: After spending most of the episode denying the obvious, Dennis finally admits that he might be coming down with something.Charlie: Are you kidding me, dude? Like, I think you're going to die.
- Comically Missing the Point: Charlie seems to think that "quarantine" is a game they're playing and at the end of the episode admits that this is why he didn't let the gang out of the bathroom, despite having had the key on him the entire time.
- Contamination Situation: The concept is played for laughs throughout the episode as the gang "quarantines" themselves in the bar to avoid getting the flu. Frank then creates a second quarantine inside the quarantine, locking the gang in the bathroom one by one as they start to get sick.
- Dark and Troubled Past: Discussed, as Dee claims that having one of these seems to be the key to winning most singing contests and suggests that they invent one.Dee: Those competitions are all about how singing helped you overcome some major obstacle, you know? So I'll do like a stutter, and I'll say I got it from watching a friend get blown to bits in Iraq.
- Definitely Just a Cold: Dennis insists he is perfectly fine despite getting more visibly, loudly ill by the day. At the nadir he eventually admits he "might be coming down with something."Dennis: Trust me, Dee, if I found myself getting sick, I would simply say: SICKNESS, BE GONE! (vomits uncontrollably)
- Dwindling Party: The gang are locked in the bathroom one by one as they each breach Frank's quarantine: first Dennis orders out for pizza; then Dee is caught hiding in the ceiling to drink beer; then Mac gets a hole in his bubble boy suit while at the convenience store; and finally Charlie wanders in of his own accord when Frank tries to shave him.
- Fan Disservice: Frank crawling around in his underwear, completely bald and covered in hand sanitizer after he shaves off all his body hair in an attempt to be "pure".
- Foreshadowing: Mac and Charlie have a conversation about Charlie's mom being an alcoholic at the convenience store, during which Mac claims that it "always skips a generation" so Charlie can't be one. The end of the episode reveals that other than Frank, the gang are all alcoholics.
- Friendship Moment: After the gang find out that the Boyz II Men concert has been cancelled at the end of the episode, Dennis states that the quarantine was still worth it because it brought them all together "in harmony". They then decide to go back and sing at the bar, which is what they always do anyway.
- Gilligan Cut:Charlie: I'm gonna be just fine.(Cut to Charlie being violently sick)
- Gross-Up Close-Up: Used from Frank's perspective as he watches Charlie eating bar snacks, and then again once he sees the particularly hirsute nurse responsible for his treatment at the end of the episode.
- Ideal Illness Immunity: Charlie claims that he can't get sick due to his mom vaccinating him every month as a child.
- In-Universe Factoid Failure: Frank apparently thinks that flu is caused by bacteria living in people's hair, causing him to shave all of his off.
- Ninja Pirate Zombie Robot: The gang's made-up backstory for the singing contest involves them being "religious stuttering army carnies".
- The Perfectionist: Dennis is this with regards to the gang's a cappella practise, to the extent that the others consider it an improvement when he's locked in the bathroom.Charlie: I thought we sounded pretty good.Dennis: We sounded pretty good? "Oh, hi, supergroup Boyz II Men, please let us win your contest! We sound, eh, pretty good."
- Pizza Boy Special Delivery: Frank's understanding of what being a pizza boy entails seems to come entirely from porn.Frank: Going house to house, handling money, banging lonely broads... They're filthy!
- Plague Episode: The episode revolves around a flu epidemic and is a parody of this kind of episode, complete with quasi-horror aesthetics. Eventually the entire Gang besides Frank becomes deathly ill, though from alcohol withdrawal, not the flu.
- The Reveal: None of the Gang have the flu. They're all alcoholics suffering from terrible withdrawal.
- Sanity Slippage: Frank becomes increasingly unhinged over the course of the episode due to a combination of cabin fever and his paranoia about getting sick.
- Sarcastic Confession: Dee does this when Frank catches her eating illicit pizza in the ceiling. He doesn't fall for it.Dee: Yes, Frank, I was eating and drinking in a ceiling! I mean, will you use your head?!
- Selective Obliviousness: Dennis spends most of the episode denying that he is sick, despite overwhelming evidence to the contrary.
- Serious Business: Dennis takes the a cappella competition that the gang want to enter extremely seriously.
- "Shaggy Dog" Story: The gang find out at the end of the episode that they Boyz II Men concert has been cancelled after the band all came down with flu.
- Shout-Out: Charlie's sketch
◊ for the gang's "matching outfit" is nearly identical to Voltron. - Skewed Priorities: The gang is clearly relieved when they realize they don't actually have the flu, they've just been going through severe alcohol withdrawal. They briefly note that it may be a problem that they're all chronic alcoholics, but shrug it off, since none of them intends to stop drinking.
- Spotting the Thread: Frank realizes that Dee has been eating pizza when she emerges from the ceiling with sauce around her mouth.
- Tenor Boy: Dennis lets out a long, high-pitched note in an attempt to try and prove that he isn't sick.
- Terrified of Germs: Frank is this for the duration of the episode, going to increasingly ridiculous lengths to try and "purify" the bar despite usually living in filth.
- Throw the Dog a Bone: Dennis offers to let Mac kick down the bathroom door at the end of the episode. He doesn't actually get to do it once it's revealed that Charlie has the key, but it's still a surprisingly nice gesture from Dennis.
- Vomit Chain Reaction: Dennis puking sets both Mac and Dee off.
