Shepard begins to doubt her own sanity when the murders start piling up - and each time a murder has taken place she has no motive as she was home-alone, unconscious after a glass of wine. At this point most people would switch to the Diet Cokes, but she keeps reaching for the bottle.
One night her ex, Jimmy, shows up at her apartment and things start to get violent. She locks herself into her room but he breaks the door to get in, and at this point she blacks out. She wakes up in bed next to Jimmy, who has been bludgened to death (and with the trademark cigarette burn on his hand). She calls the cops and is voluntarily taken into custody.
She is released when there is insufficient evidence to convict her, but thinks of her dark past and is unsure if she is capable of breaking the trend laid down by her father. Mills (Samuel L Jackson) has had a big hand to play in her fast track career and release, but warns her again to tone down her social life. The blood tests were returned from before, to show that she had a powerful sedative in her system at the time the murder was committed.
Soon enough, convinced that Delmarco has been hiding things from her, and probably drugged her, she goes to his cabin with Mills to confront him. Mills offers a toast, and Delmarco drinks from a glass of wine poured out. Mills finds a pack of Ruffees (spelling?), but Delmarco swears it's a plant, as the sedative starts to take it's toll. He slumps into his seat.
Mills starts setting up the scene to frame Delmarco, and burns his hand. Shepard has a flashback to the crime scene photo of her father's suicide and things fall in place together. Mills admits that he was responsible for the murders as his ex-partner's wife was cheating on him, and felt he had to take things into his own hands.
Delmarco manages to wake up and crawls out of the cabin, onto a raft and floats away. He drags himself up on to a pier, only to find Mills waiting for him. Mills is about to finish him off when Shepard catches up to them, and tells Mills to drop his weapon. Mills is proud that he raised her to be a good detective, and raises his weapon so she shoots him dead and his body floats away.
The detectives show up and offer her their support. Even Dale rests an arm around her, and she's finally one of the boys.