Mac (Seth Rogen) and Kelly (Rose Byrne) Radner still live in the house where they ran into so much trouble with a fraternity. Now expecting their second child, they're determined to sell the house and move on. They even have interested buyers — they just have to wait out a 30-day escrow.
The pieces are finally falling into place for these unlucky homeowners — until a newly established sorority, Kappa Nu, moves in next door. The girls, led by Shelby (Chloë Grace Moretz), and their hard partying ways are threatening the sale of the Radners' home. Desperate, Mac and Kelly turn to the one person they know can help take these crazy sorority sisters down — former neighbor and nemesis Teddy (Zac Efron).