Mr. Schuester’s high school nemesis (Neil Patrick Harris) causes trouble for the glee club; Rachel struggles with a personal issue; Artie goes on an adventure in his dreams.

A sore throat impacts Rachel’s singing; Kurt tries to impress his father; Puck hopes to elevate his social status.

Mr. Schuester investigates when a salacious list about the glee club members circulates the school; a video surfaces of Olivia Newton-John performing with Sue.

Kurt sets his dad up with an unexpected partner; April (Kristin Chenoweth) returns to save the glee club.

Mr. Schuester is concerned that the guys are disrespecting the women of the glee club; the club members perform some of Madonna’s greatest hits.

Summary: Rachel and Finn’s romance hits a rocky patch when she becomes involved with a competitor (guest star Jonathan Groff), forcing Mr. Schuester to have a talk with the competitor’s coach (guest star Idina Menzel).

When Quinn’s secret unravels, the Glee Club may not be able to finish in time to compete with the Sectionals. Meanwhile, Emma and Ken’s marriage is looming, and Sue’s scheming hits an all-time high, while Will makes a decision that could change his life forever

When the Glee Club is left out of the yearbook because of budget cuts, everyone seems to be relieved that they won’t have to suffer the ridicule of years past. Everyone except Rachel, that is, who wants her legacy cemented in print so she gets a nearby mattress store to cast them in a commercial. [...]

Will believes that Sue has been leaking information to rivaling Glee Clubs, so he visits one and also happens to get a look at their competition. Meanwhile, in order to impress Finn, Kurt gives Rachel a makeover.

Mr. Schuester splits the Glee Club into pairs to sing their favorite ballad, but when one kid gets sick, he’s forced to step in and winds up in a sticky situation. Meanwhile, Finn and Quinn have to face the music when dinner with her parents goes awry

When Artie’s chances of traveling with the group to Regionals are in question, Will challenges the kids to step out of their comfort zones and experience life from a different point of view. Meanwhile, the Glee Club hosts its first “diva-off” between Kurt and Rachel, and Sue reveals a softer side.

Inspired the by the students, Will composes a mash-up for a very special occasion. Meanwhile, in a shocking reversal of roles, McKinley High’s cool kids are dethroned in an “icy” fashion, and Sue shows off her softer side.

Sue, using her new job as the co-chair of Glee Club to her advantage, introduces tough competition to the club members.

Will challenges the kids to a healthy dose of competition with boys against girls in a mash-up showdown. Meanwhile, Terri takes a job as the school nurse, despite having no medical experience.

In order to give the glee club more of an edge, Will recruits his former classmate, April Rhodes, to spice their routines up. However, despite adding more of an edge, Will realizes he may be losing one of his members.