­In this first part of a two-part season finale, the discovery of a body in a foot locker in an exhumed grave, opens the 2005 murder case of an 18-year-old woman, Kate Butler, who went missing from a local military academy. Kate and another woman were the first two female cadets in the formerly all-male academy. Most of the cadets, the staff and alumni (including Kate's father), were violently unhappy with the change, giving the detectives a plethora of suspects. The first woman left after a week, and though Kate stuck it out and seemed to excel at everything thrown at her, she was still reviled. In the end, Rush has identified the main suspect as one of Kate's classmates, however, when she drives out to question and arrest him, she's side-swiped off a bridge and her car sinks into the river.­