From Dunder Mufflin to North Shore High School; The Office star Jenna Fischer has joined the cast of the upcoming movie musical adaptation of Mean Girls, according to Deadline. The Primetime Emmy nominee will play Ms. Heron, the mother of the main character Cady. Ms. Heron was played in the original 2004 film by Broadway alum Ana Gasteyer and by Kerry Butler in the musical's original Broadway cast.

Mean Girls is adapted from the 2018 Broadway musical of the same name, which was itself based on a 2004 hit film written by Tina Fey and starring Lindsay Lohan. In Mean Girls, new girl Cady Heron goes to high school for the first time, and realizes that there is a very clear food chain at the school, and at the top are the beautiful and vicious Plastics.

Fischer joins a previously announced cast that includes Renée Rapp, reprising her Broadway performance as Plastics queen bee Regina George; Broadway alum and Tony nominee Jaquel Spivey (A Strange Loop) as Damien; Auli'i Cravalho (Moana, Little Mermaid Live) as Janis; Angourie Rice (Spider-Man: Homecoming) as Cady Heron; Avantika (Senior Year) as the ditzy Karen; Bebe Wood (Love, Victor) as toaster strudel heiress Gretchen; and Christopher Briney (The Summer I Turned Pretty) as Regina's boyfriend Aaron Samuels.

READ: The Broadway Cast of Mean Girls Has Picked Out Their Cameos For the Movie

The film will also feature Tina Fey and Tim Meadows, who was in the original 2004 film. Though Fey's announcement of the casting on Late Night With Seth Meyers did not specify which characters they would play, other outlets have reported they will reprise their characters from the original film, with Fey as math teacher Ms. Norbury and Meadows as Principal Duval.

Fey is penning the new film's screenplay after writing the 2004 original and the stage musical's book. The score features music by Jeff Richmond and lyrics by Nell Benjamin (Legally Blonde). Samantha Jayne and Arturo Perez, Jr. are co-directing the project, with choreography by Kyle Hanagami.