Harper searches desperately for his missing daughter, praying that he will find her before it is too late. Sam has the perfect suspect, an well-known surgeon, but the only witness against him is very unstable.
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.
After a taxi driver reports a passenger who seriously gave him the creeps with his misogynistic views on women, Ali decides to look into it, and the trail leads her to Ian Summerhill, a dentist who had dated the first missing woman and had been dating the woman found a couple of days after the cabbie came in. Sam tries to investigate Summerhill's dark side and heads back to her old work place, where girls entertain men for money. Ali's relationship with Paul is threatened when Ian shares some stories of Paul's mis-spent youth with her, and she wonders how accurate they are.
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 realises 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.
When a twelve-year-old girl disappears from her bedroom, Ali and Ray infiltrate the world of pedophiles in a desperate attempt to find her.
Still torn up over his separation from Wanda, Len relentlessly pursues a serial killer as Wanda seeks sole custody of their two daughters.
After comic book Steve Baker owner is shot at, Ali takes another look into the disappearance of a young woman named Thora who everybody believed Steve had murdered. At Ali's request, Ray begins 'protecting' Steve from Thora's father David and former boyfriend Mark while trying to uncover some dirt on him. Harper is pre-occupied with his wife having kicked him out of their home, and when she and her parents cut him off from seeing Eva and Kassia, Harper finds his world falling apart.
Ali begins second guessing her actions on a past cast when lawyer Paul Deeds approaches her with the suggestion that Bryn Fulford, a man Ali and her former partner Desoto put away for murder over a decade ago, was really innocent of the crimes. Sam takes an active interest when Ray can't put aside the on-the-job shooting of suspected cop killer Boone Judson, who just happened to be the long-time nemesis of some strike force members that Sam has history with.
Sam finally gets a case of her own -- the three year old beating death of a homeless man -- which leads the squad to a company that tapes homeless people fighting to sell on the Internet.
When the squad identifies a body in the field as belonging to a young man named Joshua Stokes, Andy personally takes the news to his old friend Preston, the young man's father, and catches him in the middle of a messy divorce. His investigation soon takes him into the world of male prostitution, where he soon finds a young straight man named Rick who is trying to make a few bucks willing to give him as much information as he can. Meanwhile, Ali's friends at the station are determined to find her a man, but a disastrous bar setup and a matchmaking barbecue at Len's confirm that the only thing Ali needs a man for is occasional relief.
When a young woman dies mysteriously before what everyone assures Cold Squad was a guaranteed win in a nationally televised singing contest, the group investigates only to learn that the singer's worst enemies may have been closer to home than she thought.
When a camp counselor offers evidence that three children who died in a boating accident at camp thirty years ago were actually murdered, the Squad investigates the claims. Ali initially goes off what Goren Berkland is claiming even though there is only his word to go on, until she discovers that he lives in a mental institution and is only occasionally in touch with reality.
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.
