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.

As Will aims towards completing New Directions, a visit from his father reminds him how much this all means to him. New songs are introduced and a song originally given to a star, is given to a celibate. Will forms an all-male a cappella group, but when he neglects the glee club, the kids decide to hire a well-known choreographer to coach them. Meanwhile, Mercedes falls in love. The other six additions to New Directions are introduced. Josh Groban appears as himself.

While Kurt tries out for the football team (taking a page from the glee playbook with him), Rachel storms out of glee practice when Will gives a plum part to Tina. Meanwhile, Sue comes up with a new plot to boost her program at glee's expense; and Quinn has news for Finn.

Will decides to give New Directions some competition between them by having the boys go against the girls. Terri becomes the school nurse to check on Will.

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.

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. Meanwhile, Quinn makes it her mission to be in the Cheerios yearbook photo, and Will and Terri’s relationship is shaken to its core.

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

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