When Harper's daughter goes missing, he's convinced she's in the hands of a dangerous pedophile. Ray is drawn into an old case when a beaten wife claims her husband killed someone.

When Ali investigates a fare who disturbed a taxi driver with his misogynistic views, the trail leads to a dentist who has dated two missing women. Ali's relationship with Paul is threatened when Ian shares some stories of Paul's misspent youth.

After getting himself arrested while on a camp-out in the United States, Harper goes undercover to smoke out marijuana traffickers and, in his discussions with the squad, soon realizes that minor dealers have been dying mysteriously. His objectivity is seriously challenged when he finds himself falling for Lila, the innocent sister of one of the main suspects.

Ray responds to a call of a girl missing from her house, and under Ali's tutelage he uncovers a vital clue. Len and Sam connect the murder of a man to a long-ago World Cup match.

Len becomes involved with a murder trial because the defendant's previous husband died under circumstances Len ruled a suicide. While his custody hearing is being adjudicated, he becomes romantically involved with the prosecuting attorney.

Wanda takes Len to work, and he unexpectedly finds his bags packed in the trunk of the car. Steve Baker, a suspect in the disappearance of a teenage girl three years ago, requests police protection after someone shoots into his house.

Ray shoots and kills a suspected cop-killer, and Samantha investigates the circumstances of the murder he supposedly committed. A defense attorney persuades Ali to testify in the retrial hearing of a killer she and her former partner helped convict.

After badgering Andy to give her a case as primary investigator, Samantha looks into the case of Boxcar, a homeless man ruled to have died of "misadventure." Her case hangs on a bum fight video tape.

A skeleton is discovered and is identified as the son of a friend of Andy's, a retired Inspector. Ali and Andy quickly determine the boy was working as a male prostitute.

Len and Ali look into the death of a TV talent show contestant who collapsed while performing. Ali is peeved when Ray lists her as a reference without asking her first.

Ali talks to a man about three kids who disappeared from a camp 30 years ago, when he was a counselor, and whose bodies were discovered 4 years later. When she goes to question him further at his residence, she discovers it is a mental hospital.

When the sister of a murder victim from a case Ali worked on years before is found dead in an alleyway behind a strip club, Ali investigates the murder even though she's not officially on the police force.