The glee club works on a duet assignment, and Finn and Rachel plan to throw the competition so that Sam can have a shot at winning. Meanwhile, a love triangle between Mike, Tina and Artie develops.

Principal Figgins teaches the student body about the danger of underage drinking, and the glee club is personally touched by the message. Meanwhile, Mr. Schuester and Coach Beiste indulge in a little fun of their own.

When the entertainment for prom falls through, Principal Figgins asks New Directions to perform at the dance much to prom coordinator Sue’s dismay. Things get heated as the competition for prom king and queen draws closer, and Jessie St. James returns.

The glee kids are down in the dumps following their disappointing showing at Nationals, so Will assigns them a project to get them back on track. Meanwhile, Ms. Sylvester wants to go to Washington: Sue's running for Congress.

Congressional hopeful Sue Sylvester starts a smear campaign to ruin the candidacy of her biggest rival. Puck falls in love, and glee club directors Will and Shelby encourage some friendly competition between their clubs

When Will tries to plan a special surprise for Emma, he enlists the glee club to help him sweep her off her feet. Meanwhile, Becky sets her sights on Artie, and Finn makes an announcement about his life plans after high school that surprises the glee club.

Much to Blaine's chagrin, his big-shot Hollywood actor brother, Cooper, comes to visit.

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.

The glee club travels to Chicago, Illinois, to compete in Nationals against the best show choirs in the country, including Vocal Adrenaline, for celebrity judges including Lindsay Lohan and Perez Hilton.

In the wake of Kurt’s departure, Blaine tries to distract from his loneliness by entering the race for Senior Class President. The move puts him in direct conflict with Brittany who looks to repeat for a second term. After struggling to come up with fresh ideas for New Directions, Will begins to fear that he’s losing his enthusiasm for show choir. When an opportunity to reignite his passion and make a lasting positive impact on his students presents itself, the procrastinating Will gets prodding from two vastly different sources. After landing an internship with fashion icon Isabelle Klempt, Kurt comes up with an out-of-the-box idea to revitalize the fashionista’s sagging brand. While his initiative earns him a new mentor and earns Rachel a much needed makeover, his success also has a troublesome impact back in Lima.

The New Directions tackle an assignment, meaning the songs as well as groups that everyone is too embarrassed to admit that they love.