Casey seems to have it all - she's in the best sorority, has the most popular boyfriend, and is in-line to become the next President of her sorority that is until her dorky brother, Rusty, comes to school and is determined to join a fraternity.

Casey, in her attempt to punish Rebecca, makes her participate in a challenging scavenger hunt, while Rusty must learn to balance his studies and his frat responsibilities.

Rusty is nervous about the upcoming fraternity 'date night' due to his inexperience with women, which Cappie attempts to help him overcome much to Casey's dismay.

In the midst of the floor hockey tourney, Evan questions Casey's loyalty considering her brother and ex-boyfriend are both Kappas. Casey quells that suspicion by successfully caring out a plan to make the Kappas too hungover for their game against the Omega Chis. Rusty, desperate to play for the team but without a single athletic bone in his body, gets the help of Dale who suggests they take a scientific approach to the game. This comes in handy when, with all the brothers drunk, Cappie has no choice but to allow Rusty to play.

When the Kappa Taus have trouble making the volcano for their legendary Mt. Vesuvius party work properly Rusty volunteers to make it happen. With the help of Dale and Jen K, a ZBZ pledge, Rusty is able to steal an outmoded atmospheric destabilizing module to plant inside the volcano for the eruption effect. Meanwhile, Casey and Evan are back on track and Evan introduces Casey to his parents over dinner. However, Rebecca makes an unexpected appearance and instantly bonds with Evan's parents leaving Casey to feel like an outsider of this blue-blood clan.

On a windy, rainy night, Cappie is visited by a beautiful, mysterious girl named Destiny who turns out to be Patty the Fatty who loved Cappie obsessively since their days at camp. Over at the ZBZ house, Casey plans a slumber party to bond with the pledges but the night takes a drastic turn when Ashleigh reveals that a girl named Virginia hung herself in the house. Evan and Calvin, also braving the storm and lack of electricity, bond through the adventure of trying to kill the house rat.