As previously reported, Shelby Corcoran (Menzel), biological mother to Lea Michele's character, Rachel Berry, will have a major arc on the upcoming season that can span from 10-12 episodes.

Corcoran will return to Lima, OH, from New York to join McKinley High School as a new teacher, complicating things for Rachel as well as Corcoran's former flame Will Schuester, played by Matthew Morrison. Co-creator Ryan Murphy also said that Menzel will be involved in a "juicy" storyline with Quinn, played by Dianna Agron.

Also appearing on season three are Emmy Award winner Valerie Mahaffey and Don Most, who will play the parents of guidance counselor Emma Pillsbury (Jayma Mays); Keong Sim and Tamlyn Tomita, who play the parents of Mike Chang (Harry Shum, Jr.); Mercedes' (Amber Riley) new supportive boyfriend; the two winners of “The Glee Project,” Samuel Larsen and Damian McGinty; and the runner-up contestants, Alex Newell and Lindsay Pearce, who will be given a two-episode spotlight.

McGinty will enter McKinley in the season's fourth episode as a foreign-exchange student who Murphy said is "shacking up" with Heather Morris' character, Brittany. Larsen will play a relative of Puck (Mark Salling) who arrives later in the season.

Also on "Glee," Mike Chang (Shum) will be given two songs within the first four episodes; Will Schuester (Morrison) and Emma Pillsbury (Mays) are together and have become closer; Lauren Zizes (Ashley Fink) cuts ties with the group, but in later episodes, will have a major story with Chris Colfer's character, Kurt; and the tribute episode will be two hours long and air in the spring. As previously reported, the show's stars, Michele, Colfer and Cory Monteith, will graduate from McKinley High at the end of the upcoming season, but will not leave the show. A spin-off involving the trio was previously put on hold, but Murphy has announced that it is now back on the shelf and "if resurrected, it might not be what you thought."

The New Directions from McKinley High School will be back Sept. 20 when "Glee" returns to its Tuesday-night slot at 8 PM ET on Fox.