“On the first day of tenth grade, I got detention for a year for a Prank I didn’t commit, and now I have to break rules to try and prove I never broke any rules. It’s risky but it does have it's rewards, like rocking out with the Dudes of Darkness! I have to admit that was pretty cool. The thing is, I heard they made the song that played during the Prank, they didn’t actually make it but they did have a live recording and now I have it. But the song puts people into a weird trance, I seem to be immune to it but is it actually safe for me to listen to? I don’t mind putting myself in harm’s way to find out, but… oh man do I have to?”
Lee is running through a Laboratory carrying a folder being chased by the Cleaners. He seems exhausted and is sweating, he sudenly falls down a staircase and is knocked unconscious. The contents of the folder are spilled out as the Cleaners surround him.
The School is consumed by a flu epidemic, Lee included. Lee on the other hand is more concerned with the Prank Song still having not listened to it for fear of what it will do to him. Lee finally decides to listen to it despite the risks it presents to him. He decides it can’t make him feel any worst then the flu already has. A he listens, he seems to hear someone say "Switch the Bag".
During first period, Tina Kwee and Chaz Monorainian report on the flu pandemic. Holger Holgaart offers Lee some of his Mother’s famous “Germ go bye-bye Pie” to try and make him feel better. Lee refuses the gesture so Holger eats it himself to prevent himself from getting infected so that he can go see a new movie premiering at the theater, “Space Zombie Virus III.”
While Tina tries to calm the student body, Chaz only serves to create panic, suggesting that the flu is really the dreaded “Space Zombie flu”. Principal General Barrage Hi-jacks the Broadcast telling the student body that no one is going home until class is over, even though everyone including himself are sick, and puts the school into quarantined lockdown to enforce it.
During second period, Camillio Martinez meets up with Holger and Lee, trying to avoid getting sick so that they may go watch the Movie after school. Lee fears that the Prank song may be what has been making everyone so sick, but Camillio once again calls Lee crazy for believing that the song is anything else then just a song. Lee, so mad with fever, hallucinates that the The Red Tazelwurm is tap dancing, complete with a top hat, mustage, goatee and monacle.
Camillio fears that Lee has contracted the “Space Zombie Flu” as he displays all the symptoms (coughing, sneezing, itchy butt cramps, and hallucinations) and fears he will start acting like a zombie before long. Tina meets up with the trio in the halls, telling Camillio that there is no Space Zombie flu; Chaz was just being paranoid again.
The group spots the Cleaners installing security cameras throughout the school. Barrage announces that though he’s too sick to do it in person he’s still going to be watching everyone’s every move. Vice Principal Victoria tells Barrage that instead of spying on everyone they should let everyone go and get some rest, without success.
During Lunch hour, Biffy Goldstien and Lee report for detention. Biffy is using a sewing machine to make name tag sweaters, as his cat Mrs. Rumplekittykat has just given birth to a litter of kittens and he needs a way of telling them apart. Lee asks him to listen to the prank song to see if he can hear anything funny about it. Biffy jokes around about the hypnotizing effects the music is supposed to have apparently being immune.
Unfortunately they’ve attracted the attention of the Tazelwurm who attacks Lee for his Cell phone which contains the music.
Lee chases after the Tazelwurm in the vents with Biffy tracking both of them using their cell phones, though Biffy suggests Lee get back to detention as lunch hour is almost over. Meanwhile Camillio, Holger, Chaz and Brandy Silver are all trying to break out of the school to avoid getting sick.
Lee and the Tazelwurm suddenly disappear into a vent and off the map during fourth period, despite Biffy’s best attempts to remake contact with them. Principal Barrage suddenly hallucinates the embodiment of the flu is in his office dubbed “Colonel von Virus” a Waffen SS like soldier. Barrage and the Colonel begin struggling over the remote to lift the lockdown.
Meanwhile Lee awakens in a Lab like environment, awakened by the Tazelwurm which once again, since Lee is hallucinating, appears to act and talk, particularly talk, like a British Gentleman. The Taz explains that he attacked Lee because he was playing the Prank song offering to show Lee why he hates it if he follows him.
Meanwhile, Chaz, Holger, Camillio, and Brandy make it to the back doors, discovering that they’ve been locked. Thinking like the main characters in the Space Zombie trilogy the group decides to go to the roof to escape the lock down. The Colonel has won the struggle over the remote, he prepares to release the disease infected students but Barrage sprays him with disinfectant.
Finding a weakness at last, Barrage orders the Cleaners to spray the entire school with disinfectant. Lee and the Tazelwurm are avoiding the Cleaners, while hiding Lee spots a group of Scientists talking to the Cleaners, among them his father. Lee’s sneezing attracts their attention but the Tazelwurm saves him from getting caught.
Meanwhile Holger and the others are making their way to the roof. Camillio spots a pair of Cleaners and steals their disinfectant filled super soakers to fight off the hoards of students with. While being chased by their classmates Cyrus Xavier sneezes on Camilio infecting him, the group is able to finally make it to the roof while they ditch their classmates in the boys bathroom.
Back to Lee and the Tazelwurm, the later has brought Lee into a laboratory, where the Tazelwurm explains that this is where the music was developed. He explains that the Flu is just a normal flu; it has nothing to do with the Prank music. Lee asks why the Music doesn’t affect him or Biffy, with the Tazelwurm telling him that they’re naturally immune, an uncommon trait like the ability to roll one’s tongue.
Back to Barrage and the Colonel, Barrage has apparently defeated the Colonel; however he summons legions of Flu soldiers to defeat Barrage. Camillio and the others arrive at the roof top only to discover that their way down has been destroyed, worst yet Camillio has started to show symptoms of the flu. Brandy and Chaz try to force Holger to disinfect Camillio and send him back to the zombies.
Back to Lee and the Tazelwurm the latter has given Lee a folder, everything he ever wanted to know about the Prank Conspiracy and more. Lee looks through the folder and discovers that it’s all about him, including a picture of himself and his family in Asia when Lee was just a infant, Lee commenting that he doesn’t remember being there. The Tazelwurm tries to explain that it’s all a game, with Lee at the center of its conspiracy.
Before the Tazelwurm can explain more the Cleaners break into the Lab, the Tazelwurm attacks them so that Lee can escape. Meanwhile Camillio is trying to talk Holger out of spraying him, but Brandy and Chaz convince him otherwise. At the same time Barrage has defeated the Colonel but he’s still able to release the student body when the bell rings.
Realizing that they can get back down again Chaz runs down the stairs, in the process tripping and hurting himself and getting the flu as well, Brandy also leaves leaving Camillio to ask Holger if he really would have sprayed him. Picking up where the Preview left off, the Cleaners have dragged Lee’s unconscious body back to detention, Lee believes that the entire incident was just a fever induced dream.
Biffy arrives again, telling Lee that he lost him in the vents. The Tazelwurm gives Lee back his phone and Vice Principal Victoria dismisses Lee early seeing he’s sick. Once home, Lee is enjoying a bowl of Chicken noodle soup in his room, Holger and Camillio call Lee, the first of which has bought enough space zombie masks for the three of them.
Lee asks his father if he was at his school today to which he denies, this confirms Lee’s belief that he just fell asleep and dreamt the whole thing. Meanwhile back at the school, in the laboratory, the Tazelwurm is seen smiling as he escapes again.
Vice Principal Victoria checks in on Biffy and Lee, she notes that Lee is too sick to be in school today and therefore dismisses him from detention early. Biffy attempts to fake the flu to get out of detention too but Victoria sees through the failed attempt and leaves without dismissing him. Biffy opens a Filing cabinet which contains Mrs. Rumplekittykat as well as her six kittens: Snugs, Wiskers McGee, Blinky, Fluffy Flop, Snaggy and Pewcat.
Biffy reminds the six kittens that in a week they will be ready to go to their new homes, unfortunately Snugs runs off and Biffy chases after him, having to fight off the Cleaners by tackling one and locking the other in a closet before retrieving Snugs and returning to detention. With Snugs reunited with his family Biffy checks his computer and realizes someone downloaded something from it, stating whoever it was is going to pay.
This episode is a homage to the horror-thriller film 28 Days Later, especially the title of the episode. The plot of the movie revolve around a handful of survivors who try to find sanctuary after a mysterious, incurable virus spreads throughout the UK.
The flu may have spread via Giuseppe Stern; he was shown sneezing in episode 6.
Of all the characters shown in the episode, there are very few who are not sick at any time throughout the episode. They are: