In the series finale, the Kappa Taus try to stop the demolition of their house. Meanwhile, Cappie and Casey come to a realization about their on-again, off-again romance; and Cappie and Evan determine whether their friendship is meant to last.
Rebecca seeks help from Frannie when she learns ZBZ may be crowned best chapter in the country, and Frannie then attempts to win over the national reps by claiming she can get a big celebrity to perform at a special concert.
A snowstorm hits town and strands the gang at Dobler's on Calvin's birthday. Friendships and romances are then put to the test when Casey finds out about Ashleigh dating Prof. Segal and Rebecca questions the staying power of her relationship with Evan.
Rusty awakens with a hangover and memory lapse from the night before. As he tries to piece together what happened, he discovers he shared a surprising kiss. Elsewhere, Casey spends an unplanned evening with Cappie; and Katherine asks Casey for advice.
Cappie strives to win over Peter's father (Jonathan Silverman) while planning an outrageous homecoming party. Meanwhile, Rusty hopes to impress Peter by stealing a mascot; and Ashleigh's lack of career motivation leads to a fight between her and Casey.
Beaver and Casey search for his elusive online tutor after Beaver gets caught turning in a paper he bought and Casey finds herself without a study group. Meanwhile, Rebecca uses a pledge event to make Evan jealous; and Rusty recruits Ashleigh to help him with a presentation.
Rusty makes plans for Dale at a murder-mystery party. Elsewhere, Ashleigh drops by ZBZ for a surprise visit; Casey's new law-school classmates spread rumors about her; and Cappie and Calvin work together on a philosophy project.
In the fourth-season opener, Casey and Evan enter law school while Ashleigh struggles with starting her career in New York City. Elsewhere, Rebecca begins her tenure as ZBZ president; and Rusty tries to get Cappie to step down as president of KT.