◄"Environmental Science"► Directors: Seth Gordon — Writer: Dan Harmon — Aired: November 19, 2009 — Season: One — Number: Ten Summary: Jeff hangs out with Señor Chang to get out of writing an essay. Meanwhile, Abed and Troy search for their missing lab mouse and Pierce helps Shirley with a presentation.
In the school cafeteria, the dean is making an announcement about the upcoming week-long school environmental awareness event called Green Week. Afterwards, the study group finishes taking a Spanish exam when Chang tells them to put their pencils down. Annie wasn't paying attention and continues writing. He stops her and drags her desk- with her still in it- out of the classroom. Shutting the door in her face, he addresses the class and assigns them all a one page essay. When Pierce asks him a question, he ups the page count to two. After Shirley objects, he ups the page count to six. When Britta attempts to compliment Chang, he interprets it as sucking up and assigns twenty pages for the essay due on Monday.
"Well listen up handsome hobo, your gravy train is leaving the station"
Back in the study room, the group is freaking out over Chang's latest insanity. All of them are busy with other classes and don't need the added pressure of a twenty page essay. Shirley is so worried about a presentation due in her marketing class that she accepts when Pierce volunteers to help. Troy and Abed chime in that they are already behind in a science project involving rats, one of Troy's phobias. Britta says that someone needs to talk to Chang and try to reason with him. Annie nominates Jeff who argues that he doesn't want to risk his grade by making himself a target of Chang's wrath. After Britta, Annie, and Troy wear him down, he grudgingly agrees to talk to Chang.
In Chang's office, Jeff discovers that Chang has separated from his wife, and the resulting emotional void is responsible for the excessive work assigned to the class. To cheer him up, Jeff invites Chang to hang out, and Chang offers to cancel the essay for Jeff but not the rest of the class. Meanwhile, Troy and Abed are training their rat, Fievel, to respond to their singing when it escapes.
Fievel goes Hollywood.
The next morning, Jeff, hung over after a late night with Chang, tells the study group that he was unable to make any progress with their Spanish class. Pierce tutors Shirley in public speaking, but his generally derogatory and offensive manner discourage her, and she decides to just read her presentation off of notecards. During class, Chang adds a quiz for next Monday, but when he thanks Jeff for turning in the essay early, the group realizes Jeff sold them out. Jeff continues to spend time with Chang in his office, but Chang threatens to fail him should he spend time with other teachers. Jeff recognizes that Chang's emotional need is far greater than it first appeared.
Chang shows up at the school dance commemorating Green Week at Greendale, curious about why Jeff invited him only to see his wife waiting to dance. As the dance starts, Shirley begins her speech in the marketing classroom but falters when the professor tells her he does not allow cards. With Pierce's coaching from the back of the room, Shirley quickly recovers and finishes her speech to a standing ovation. At the same time, Troy overcomes his initial reluctance to help Abed find Fievel and sings their duet which allows them to recapture the rat. Back at the dance, Chang begins passionately making out with his wife on the dance floor. He suddenly stops, jumps on stage, and tells the crowd that he has been a horrible teacher and husband and calls off the essay for everyone but assigns a short essay to Jeff for betraying his friends. The study group, seeing that Jeff found a way to help all the students, forgives him and offer to help with his essay.
Abed and Troy are preparing for a water gun battle. They mock Pierce when he shows up with a tiny water pistol. They both stop laughing when he shoots them in their eyes with the pepper water that's inside.
Pierce makes a joke with no response but when Jeff gets a big laugh for making the same joke Pierce asks, "What is it? The chair?" Later in the episode, when Jeff misses a study meeting Pierce sits in the vacant spot and has more success with his quips. Then, in the first episode of Season 3, Biology 101, Jeff is again separated from the group and blames his resulting erratic behavior on lack of contact from the study table, claiming it has magical powers.
Dean Pelton watches an unsettling video featuring a man wearing a suit with a dalmatian pattern and says, "This better not awaken anything in me." Later in the season, his office features dalmatian decorations  and he invites dalmatian furries to join him at the Tranny Dance in Pascal's Triangle Revisited.
History lesson: Chang tells Jeff how he met his wife and why they separated.
School supplies: In Chang's office, there is a picture of his wife with a little speech bubble added that says : "enjoy it while it lasts".
Dean Pelton announces that Green Day will perform at Greendale. However, he was mistaken and the band is actually a traditional Celtic group with the homonymic name Greene Daeye.
Several Biology students sing songs to their rats, including Mary Had A Little Lamb and Row, Row, Row Your Boat. Abed and Troy sing Somewhere Out There.
IMDB: Abed and Troy's rat is named Fievel after the main character from An American Tail. The song they sing to Fievel features prominently in the movie. Additionally, the reunion of Troy, Abed, and Fievel is reminiscent of a scene in the film.
While teaching Spanish Chang calls Shirley "Shakira" and Troy "Tupaco".
Pierce tells Shirley that the best way to end a presentation is with a Jack Nicholson quote. She chooses to say "Here's brownie!" a variation of the famous line Nicholson delivered in The Shining.