Naomi decides to go green and she wears sweats to school, much to her friends' shock. Next week on "90210", Naomi learns that her test scores may not be high enough for her to be accepted into CU. Devastated, Naomi devises a plan to be tutored by Richard, the son of the school's dean of admissions, but quickly realizes she would much rather be studying Jamie, a CU student.
Meanwhile, Dixon's girlfriend, Sasha, becomes suspicious about his age and does a little detective work to learn the truth, leaving Dixon devastated. Navid and Adrianna double date with Teddy, but Adrianna's growing feelings towards Teddy make for an awkward situation.
Silver accompanies Adrianna to an AA meeting and surprisingly bumps into her mom, Jackie, who tells Silver she would like to re-establish their relationship. An angry Silver rejects her mother, but her world is turned upside down when Adrianna reveals shocking news about Jackie.
The episode is called "Environmental Hazards" and it will air on Tuesday, October 6. Jonathon Trent guest stars as Richard, Travis Van Winkle as Jamie, Mekia Cox as Sasha and Ann Gillespie as Jackie.