Optimistic high school teacher Will Schuester tries to refuel his own passion while reinventing the McKinley High School’s glee club and challenging a group of outcasts to realize their star potential. Going up against McKinley’s cruel high school caste system and facing harsh criticism from everyone around him, Will is determined to prove them all wrong.

As McKinley High School's glee club begins new routines, a restriction forces them to make some choices. Will must decide whether to continue with his passion or provide for his wife, which ultimately brings him closer to Emma. As some members of New Directions grow closer romantically, other's intentions aren't supportive of the group.

Will thinks the glee club desperately needs more of an edge, so he brings in his former classmate, April Rhodes, to spice things up. Will’s plan seems to be going smoothly until he realizes he may be losing a key member of the club.

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.

Concerned that Sue is up to no good, Will pays a visit to an instructor of a competing Glee Club to see what information Sue may be leaking, which leads to the club getting a look at their hair-rising competition. Meanwhile, Kurt gives Rachel a makeover to impress Finn, but he may have ulterior motives.

Fresh off their monumental win at Sectionals, New Directions is on top of the world. With an extra spring in their step, they get to work on new numbers for regionals. But when Rachel and Finn’s budding romance hits a bump in the road after she becomes involved with a competitor, Jesse St. James, it threatens to derail the entire club. Mr. Schuester pays a visit to Shelby Corcoran, coach of Vocal Adrenaline, to confirm Jesse’s motives. Meanwhile, Will is newly single, but is he ready to take his relationship with Emma to the next level? And to top it all off, Sue Sylvester returns from her condo in Boca with a renewed focus on destroying Will and disbanding the glee club.

Mr. Schuester starts an investigation when a salacious list about members of the glee club circulates the halls of McKinley High. Meanwhile, Sue is mortified when a video of her performing the Olivia Newton-John classic "Physical" surfaces

Mr. Schuester encourages the glee club to express themselves using the music of Lady Gaga. Meanwhile, Rachael has a life-changing encounter, and Tina embraces her inner Goth.

The glee club gets some news that’s sure to rattle a few nerves. Meanwhile, Quinn connects with her “funky” side with a little help from Mercedes, and Will gets revenge on Sue.

After a tough loss at Regionals, the glee club is back as the underdogs of McKinley High. When the school is faced with even more budget cuts, Mr. Schuester pushes the kids to help recruit new members for the club. Rachel and Finn disagree on new recruits, and aren’t sure they will be able to come together in perfect harmony.

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.

When Mr. Schuester gets sick, a substitute teacher takes over his Spanish class and the glee club and winds up winning over the whole New Directions clan. Meanwhile, when Sue fills in for Principal Figgins as McKinley’s top dog, she tries to flex her power on campus.

It's Christmas time at McKinley High and Finn tries to get everyone in the holiday spirit; Brittany needs no help because she still believes in Santa Claus. In other news, Sue scams the teacher's Secret Santa

A local football championship game takes place and the "Thriller" mash-up is performed during the halftime show. The Cheerios, McKinley High's cheerleading team, compete at Regionals.

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.

The glee club agrees to help raise funds for another under-the-radar group; big decisions are made and relationships are tested.

Sue Sylvester revives the school newspaper and decides to print a few inflammatory blind items. The glee club gains a whole new respect for Sam when they discover some interesting new information about his family life. Meanwhile, April Rhodes (guest star Chenoweth) returns to Lima and tries to convince Mr. Schuester to hit the road with her.

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.

Emma gets a visit from her parents; Mike Chang's parents get involved when his grades aren't up to their standards.

Will assigns the glee club a Spanish singing assignment, and enlists the help of his musically-inclined night school teacher. Meanwhile, Rachel spills the beans to Kurt and Mercedes on Finn's marriage proposal, and Mercedes has love complications of her own.

Tina's head injury from falling into a fountain leaves her seeing her fellow singers and other people at McKinley High in a new way as rehearsals continue for the glee club's Nationals performance.

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.

A love triangle heats up among Marley, Jake and Ryder, and Blaine has a run-in with the Warblers.

Will and Emma get ready for their Valentine's Day wedding with the help of past and present New Directions members.

It's finally time for Regionals, and the glee club is more determined than ever to advance to Nationals. Brittany returns from her MIT trip with a new attitude and Ryder finally has a lead on who is "catfishing" him.

As the Prom approaches, the race for Prom Queen brings out the best and the worst in candidates Tina and Kitty. Meanwhile, Sam tries to make a connection with a new school nurse, an increasingly discouraged Rachel waits for word on her Funny Girl callback, and Santana makes a new friend at work.

The New Directions remember Finn.

After Rachel's humiliating failure as TV actress, she comes home to Lima to figure out what she wants to do next. Upon discovering that Sue has banished the arts at McKinley, Rachel takes it upon herself to reinstate and lead the Glee Club. Meanwhile, Blaine, no longer in a relationship with Kurt, has moved home to coach the Warblers while Will is coaching rival Vocal Adrenaline, and Sam is the assistant coach for the McKinley football team.

Rachel hopes to form a deal in which Will's glee club purposefully under-performs at their invitational; Sue wants Sam to distract Rachel.

Rachel and Kurt redouble their efforts to recruit new members to New Directions after new rules are announced for the Show Choir Invitational. Sue enacts an elaborate plan to try reunite Kurt and Blaine. Will and Rachel have a much needed heart-to-heart.

GLEE goes back in time to see why the original members of New Directions signed up for glee club in the first place.

All of Will’s hard work and dedication to the Glee Club and to fostering the talents and dreams of his students pays off in a major way, and everyone shares in the feeling of joy that permeates the school as teachers and students reflect on their shared journey. Old rifts and wounds are healed and new sights are set on a promising future. Everyone seems to be ending up exactly as expected and right where they belong… along with more than a few unexpected surprises.