Gwyneth Paltrow debuts as guest star in this episode, portraying Holly Holliday, a substitute Spanish teacher who takes over the New Directions when Will gets sick. She sings three songs in this episode: one as a duet with Rachel, one as lead with the New Directions, and one as a duet with Will, with back-up from the New Directions. Jessalyn Gilsig returns for her role as Terri.
Cheerleading coach Sue Sylvester is appointed acting principal of William McKinley High School after having Principal Figgins infected with the flu. Glee club director Will Schuester is also infected, he sees the kids as if they were toddlers, meaning he has to have at least a life-threatening fever of 41C/105.8F fever to be hallucinating this severely, then he takes time off work to recover. He is cared for by his ex-wife Terri and the two begin to reconnect and end up sleeping together.
Will's lessons are covered by substitute teacher Holly Holliday, whose unconventional methods include discussing Lindsay Lohan in Spanish, singing Conjunction Junction in English, and roleplaying as Mary Todd Lincoln (Mary Todd Lincoln in the house!) in History. She agrees to take over the glee club (at Kurt's urging) in Will's absence and impresses the entire club, minus co-captain Rachel Berry, with her rendition of Cee Lo Green's Forget You (also known as F*** You). She later wins over Rachel by duetting with her on Nowadays/Hot Honey Rag from Chicago. Will has a dream , performing Make 'Em Laugh with Mike and then woke up with a feverish state.
Club member Kurt Hummel neglects his best friend, Mercedes Jones, in favor of his new friend Blaine Anderson. Mercedes is offended when Kurt tries to set her up on a date with a football player on the basis that they are both black, and feels left out when she accompanies Kurt and Blaine to dinner, where conversation is dominated by gay issues and icons. When Sue begins a healthy eating initiative and declares a ban on Tater Tots, Mercedes takes a defiant stance, because she feels that it is her right to choose what she eats for lunch. She organizes a student protest and fills the tailpipe of Sue's Le Car with Tots, which according to Sue caused $17,000 worth of damage to the car.
Sue's initiative proves popular with the students' parents and her appointment as principal is made permanent. Meaning that she essentially has the power to achieve her lifelong dream of disbanding the Glee Club, which she does not do. She fires Will, who is later visited by Holly seeking advice. Holly feels out of her depth as a teacher, having enabled Mercedes' behavior. She confesses that she originally took her work seriously until a student punched her in the face, prompting her more laid-back approach. Terri arrives while they are talking and is angered by Holly's presence. Will tells her that their reunion was a mistake and asks her to leave his apartment and never return.
Kurt confronts Mercedes, suggesting that she is substituting food for love and their friendship for a romantic relationship. Mercedes agrees to talk to Anthony, the student Kurt attempted to set her up with. As she departs, Kurt is approached by school bully Dave Karofsky, who threatens to kill him if Kurt reveals his closeted homosexuality. Kurt is terrified by this threat and temporarily unable to move.
At the urging of the glee club members, Sue re-instates Will. Even though Sue can, seeing as she is the Principal, easily disband the Glee Club, which she has attempted to do so for nearly every episode she has appeared in. He suggests a group performance of Singing In the Rain, but the kids aren't into it. He asks for Holly's help to modernize it, resulting in a mash-up with Rihanna's Umbrella.
|Song Title||Original Artist||Performer(s)|
|Forget You||Cee-Lo Green||Holly Holliday and New Directions|
|Make 'Em Laugh||Cast of Singin' in the Rain||Will Schuester|
|Nowadays/Hot Honey Rag||Cast of Chicago||Holly Holliday and Rachel Berry|
|Singing in the Rain/Umbrella||Cast of Singin' in the Rain/Rihanna feat. Jay-Z||Holly Holliday and Will Schuester|
with New Directions
- Conjunction Junction from Schoolhouse Rock sung by Holly Holliday.
Special Guest Star
- Iqbal Theba as Principal Figgins
- Dot-Marie Jones as Shannon Beiste
- Harry Shum Jr. as Mike Chang
- Chord Overstreet as Sam Evans
- Max Adler as Dave Karofsky
- Darren Criss as Blaine Anderson
- Lindsey Sims-Lewis as Cameo
- Loanne Bishop as Waitress
- Ashley Fink as Lauren Zizes
- Ryan Heinke as Stoner Brett
- Lauren Potter as Becky Jackson
- Alexys Alonzo as Mini Santana
- Lauren Boles as Mini Rachel
- Loryn Shay Charbonnier as Mini Brittany
- Jada Harris as Mini Mercedes
- Evan Kishiyama as Mini Mike
- Matthew Lepper as Mini Puck
- Jake Vaughn as Mini Finn
- Landon Zakhar as Mini Artie
- Connor Berliner as Mini Sam
- Avery Phillips as Mini Quinn
- Gwyneth said that the Singing in the Rain/Umbrella performance was so fun to do. She said she felt like a kid again.
- Kevin commented that he got stuck in the wheelchair during Singing in the Rain/Umbrella because Lea Michele and the others made a competition out of kicking water towards him, soaking him.
- It is ironic that Kurt tells Mercedes he doesn't want another Rachel-Jesse traitor debacle with Blaine, when Blaine himself gets into the same situation with Sebastian in Season 3 (When Blaine tells Sebastian New Directions was planning on doing Michael Jackson for Regionals).
- In the episode Throwdown, Finn mentioned Gwyneth Paltrow while talking baby names with Quinn, saying how he thinks it's cool she named her baby Apple because he likes apples. In this episode, Gwyneth Paltrow appears as The Substitute.
- Dominic Barnes, who currently plays Trent, also plays a student who can be seen in Holly Holiday's Spanish class.
- Lindsay Lohan is mentioned by Holly during her Spanish class. She appears as a judge in Nationals episode.
- Sue calls Mercedes "Jackeé early in the episode, ironically enough, Jackeé Harry guest starred as a judge in, City of Angels.
- During the scene where Will imagines the Glee Club as 5 year olds, in the scene before Quinn isn't seen, but her mini-me is. This is due to her being sick on the day of shooting.
- In the scenes with Rachel and Puck suggesting songs to perform they are wearing the same clothes, but Will seems to have taken his time to think about the Journey songs and find one that hasn't been performed.
Brett: Are you on anything? 'Cause this is trippy.
Mary Todd Lincoln in the house! My husband was probably gay, and I'm bipolar, which makes me yell about things like "That teacup is spreading lies about me" or "This can't be my baby, because i don't love it."
Rachel: Now, class, I want you to all go around and discuss what songs they'd like to hear me perform at sectionals.
I suggest selling yourself on Craigslist under the heading of 'Men seeking Men with butt chins.'
You make the underflaps of my breasts burn, like when I used to rub them with poison sumac.
Will: When I'm sick there's only one thing that makes me feel good.
These guns are fully loaded.
—Mini Noah Puckerman
Shannon: Can I help you, Sue?
Sue: Principal Sue.