At World's End - S2.E22

After she falls into a manhole risking her life, coupled with the Kappa Tau's throwing an "End of the World" party, Casey is sent into an emotional tailspin, questioning her relationship with Max and her lingering feelings for Cappie. Meanwhile, Ashleigh faces her own punishment with Pan Hellenic after a complaint is lodged by Frannie for the Homecoming Float sabotage. Ashleigh turns to Casey to help fight the charge, but when Casey gets caught up in her own personal drama, she leaves Ashleigh to face Frannie alone. And with Dale having trouble keeping his cougar girlfriend's sexual advances at bay and Calvin trying his best to resist hooking up with his new hot roommate, Grant. Dale convinces Calvin to go in on a "purity pledge" partnership so they can help each resist their most recent temptations.