Glee club is back in session!

Shelby Corcoran (guest star Idina Menzel) returns to the halls of McKinley High. Meanwhile, Mr. Schuester initiates a boot camp for some of the members of New Directions. Musical performances include “Somewhere”, “I’m The Greatest Star” and “Something’s Coming”.

Parents just don’t understand.

A foreign exchange student gets lucky.

Under Artie’s directorial leadership, the kids prepare to perform the school musical “West Side Story.” Meanwhile, Finn meets with a recruiter, and Coach Bieste has an admirer. Musical performances include “Tonight”, “Uptown Girl”, “A Boy Like That”, “America” and “One Hand One Heart”.

Sue starts a smear campaign to take down her biggest competitor for the Congressional seat. Meanwhile, Puck has a crush, and Will and Shelby Corcoran encourage some friendly competition. Musical performances include “Hot For Teacher”, “You And I”, "Hit Me With Your Best Shot", "One Way Or Another", “I Can’t Go For That (No Can Do)”, “You Make My Dreams”, “Rumour Has It” and “Someone Like You”.

As the race for McKinley High President comes to an end, someone is caught trying to fix the results. Meanwhile, Coach Beiste gets up the nerve to challenge Sue Sylvester and things get complicated for Puck and Quinn. Musical performances include "Perfect", "I'm The Only One", "Girls Just Want To Have Fun", "Jolene", "I Kissed A Girl" and "Constant Craving".

McKinley High hosts sectionals.

It's Christmas time at McKinley High.

Love is in the air at McKinley High.

The King of Pop reigns in Lima.

The New Directions are livin' la vida loca.

Finn meets the parents.

Things heat up as the New Directions go head to head with the Dalton Academy Warblers at Regionals. Musical performances include “Cough Syrup”, “Stand”, “Glad You Came”, “Fly/I Believe I Can Fly”, “What Doesn’t Kill You (Stronger)” and “Here’s To Us”.

Much to Blaine’s chagrin, his big-shot Hollywood actor brother, Cooper (Guest Star Bomer), comes to visit. Musical performances include "I'm Still Standing", "Fighter", "Up Up Up", "Hungry Like The Wolf/Rio" and "Somebody That I Used To Know".

The New Directions pay homage to the movie "Saturday Night Fever" by grooving to disco-infused dance numbers. Musical performances include "You Should Be Dancing", "Night Fever", "Disco Inferno", "If I Can't Have You", "How Deep Is Your Love", "Boogie Shoes", "More Than A Woman" and "Stayin' Alive".

The glee club pays homage to a true icon when they cover Whitney Houston’s greatest hits. Meanwhile, Emma and Will are one step closer to their dream wedding. Musical performances include "How Will I Know”, “I Wanna Dance With Somebody (Who Loves Me)”, “Saving All My Love For You”, “So Emotional”, “It’s Not Right But It’s Okay”, “I Have Nothing” and “My Love Is Your Love”.

Rachel and Kurt finally get their chance to audition for the New York Academy of the Dramatic Arts. Meanwhile, Puck makes a decision about his future after a meeting with his father. Musical performances include “School’s Out”, “Cell Block Tango”, “Not The Boy Next Door”, “Don’t Rain On My Parade”, “The Rain In Spain”, “Shake It Out” and “Cry”.

Brittany goes into high gear as class president to spearhead the prom. Then, after prom king and queen nominations are announced, the kids kick into campaign mode, and some of the outcasts organize a rival celebration. Musical performances include “Big Girls Don’t Cry”, “Dinosaur”, “Love You Like A Love Song”, “What Makes You Beautiful” and “Take My Breath Away”.

The kids prepare a high-concept routine as Nationals approach.

New Directions compete at Nationals in Chicago. Lindsay Lohan (playing herself) is a guest judge.

In the Season Three finale, graduation is finally here, as McKinley High’s class of 2012 looks to the past and present, while contemplating the future. Musical performances include “Forever Young”, “I’ll Remember”, “In My Life”, “You Get What You Give”, “Glory Days” and “Roots Before Branches”.