A fifteen year old girl goes missing and her blood-stained clothes are found. Det. Supt. Walker heads the investigation into her murder. Meanwhile, D.I. North is sent to see a persistent complainer, Warrington, who has been hounding the station. North begins to get stalked and Walker has a prime suspect for the murder. But then they find a connection between Warrington and Walker's prime suspect.

DS Satchell is desperate to find his wife and daughter now that they are misssing. Walker and Connor try to find the evidence to put the Bilkin family behind bars. Satchell decides to take matters into his own hands when he feels he has nowhere else to turn.

Terry Dyer has been recently released from prison, where he was imprisoned for a crime he still maintains he did not commit, and he returns to his East London estate in search of the truth. The father of the victim he was convicted of killing, Ken Randle, confronts and wounds him. D.C.S. Walker is empathetic to Ken's situation and releases him on bail, and then Ken soon becomes doubtful of Dyer's guilt, growing convinced that a friend of his son's was involved in his murder, and soon long-buried secrets are unearthed, leading to an unexpected twist, while D.S. Satchell finds his career may be in danger.

The aftermath of Gary Webster’s suicide begins – a DPS enquiry, a very shaken Palmer, and a shocked but stoic Gemma, still convinced of a cover-up at the hospital. Gary wasn’t the killer; all he ever wanted was a straight answer. Adrian Lawson offers a video recording of Amber’s surgery, showing that it was purely straightforward procedure, nothing untoward. His helpful nature doesn’t convince Connor, noting that he wouldn’t have given them something that might implicate either him or the hospital. In any case, Amber died in the ICU, six hours after the surgery. To get to the truth, they need to go back to whoever was in the ICU that night. Walker is unhappy about what he sees as his team wasting their time investigating hospital negligence, when Carlisle’s killer has still not been found. However, Connor is convinced of a connection between his murder and the death of the Webster’s little girl. Connor’s hunch nags at Walker and he pays a discreet visit to Gemma Webster. Promising that the police are investigating the case fully and properly, and revealing that Carlisle was killed with a massive overdose of fentanyl, he asks her once more if she has any information she hasn’t revealed so far. Gemma says nothing. With the spotlight of suspicion now falling on Lawson, Walker questions the Lawsons again. Adrian expresses shock and surprise when told that he was being implicated in Amber’s death. Adrian’s loyalty to his former boss and mentor starts to fade as, seething, he suggests that Walker look at what Carlisle was up to that night…

The apparently happy Harrogate family is torn apart when they return home to discover their daughter, Emily, dead. Connor and Satchell begin to sift through the case and discover that the family isn't as stable as it first appeared. Connor appeals to Walker for some backup, who is having problems of his own with his own son Richard. Secrets are soon discovered and fragile relationships are tested in the process of ensuring justice is done.

A fifteen year old girl goes missing and her blood-stained clothes are found. Det. Supt. Walker heads the investigation into her murder. Meanwhile, D.I. North is sent to see a persistent complainer, Warrington, who has been hounding the station. North begins to get stalked and Walker has a prime suspect for the murder. But then they find a connection between Warrington and Walker's prime suspect.

Despite the presence of Tess, the police find the funfair workers unwilling to cooperate. An arrest is eventually made, a Romanian worker called Pavel, who had actually gone out with the girl who fell from the Big Wheel, but he is not the murderer. The big question still remains as to the part the development company may have played in the deaths at the fair.

When a girl falls to her death from a ferris wheel, it is thought to be a tragic accident - until DS Satchell's aunt comes forward with suspicions of foul play.

A young school girl is raped and murdered, but D.C.I. Connor still has no leads a month into the investigation. When Walker orders a review of unsolved cases, they turn up similar cases of raped and murdered teenage girls over the last ten years, and they find themselves searching for an apparent serial killer.

When items relating to the case are found in Dunn's flat, Walker has no doubt that Dunn is responsible. However, when it's revealed that a frantic young officer who found Julie's body planted evidence, Dunn's trial is thrown into jeopardy.

When Susan Harrow does not return home, her mother reports her missing to the police. Her body is later discovered on wasteland and an investigation is launched, once again headed by Walker. Following a second murder, the team realise that they have a serial killer on their hands.

D.C.S. Walker goes on leave back to Glasgow, where he is taking care of his increasingly senile mother, he soon becomes involved in the case of a missing woman, who is the sister of an old friend. Walker begins to delve into the life of her then husband Kevin Reid, and discovers a dark bond between him and his brother Ronnie. Soon a body is discovered and is it is proved to be the missing woman. Then Kevin's second wife is reported missing - convincing Walker that one or both of the Reid brothers are involved in the crimes.

A severed female hand is found in the Thames, which brings D.C.I. Conner in contact with Walker (who is now back in uniform). No body is discovered, and the case soon becomes a battle of wits against the killer.

A severed female hand is found in the Thames, which brings D.C.I. Conner in contact with Walker (who is now back in uniform). No body is discovered, and the case soon becomes a battle of wits against the killer.

D.I. North re-investigates an eight-year-old murder case and finds that Det. Supt. Walker was in charge of the inquiry. She begins to suspect that he's covering something up and he is suspended from duty. He returns to his roots to find new evidence to prove his innocence, in order to save his career, relationship and reputation.

A young prostitute, Angela Dutton, plunges to her death from the eleventh floor balcony of a block of flats. The police begin a murder inquiry and discover that she was the daughter of a seventies TV star who was also found murdered twelve years earlier, wrapped in blue eiderdown. The killer was never found. D.C.S. Walker heads the investigation into the two murders, with the aid of D.C.I. Connor and the rest of the team. They investigate to find out why Angela Dutton died - did she find her mother's killer, or did one of her three high-paying clients kill her?

D.I. North investigates when a girl is snatched from a wood, but the confession of a local sex offender complicates matters. Detective Chief Superintendent Walker is little help, as he has worries of his own.

A serial rapist is targeting the black community by raping white women with black boyfriends. When an attack ends in murder and the boyfriend is cleared, Walker brings him on to the investigation to help, but could Connor's relationship with a barrister working on the case jeopardise the investigation and the subsequent trial?.

A young prostitute, Angela Dutton, plunges to her death from the eleventh floor balcony of a block of flats. The police begin a murder enquiry and discover that she was the daughter of a seventies TV star who was also found murdered twelve years earlier, wrapped in blue eiderdown. The killer was never found. D.C.S. Walker heads the investigation into the two murders, with the aid of D.C.I. Connor and the rest of the team. They investigate to find out why Angela Dutton died - did she find her mother's killer, or did one of her three high-paying clients kill her?

A mother returns home from work to find her baby girl dead in her cot, and her nanny has Vanished. D.C.I. Connor and the team take on this emotive case involving this ultimate abuse of trust. With the nanny on the run, it seems an obvious conclusion. But the more they investigate the case, the more complicated it becomes and they find themselves wondering who is the real victim and who can they really trust?.

Another working girl, Maryna, is put on trial for assaulting Malikov. She claims self-defence but the trial is mishandled and walker is even more adamant then before that he will get the Ukrainian. Roisin, however, believes that his obsession with Malikov is blinding him to the identity of the real killer of Sonya and takes the investigation down a different route.

Marilyn Spark's identification of Morton as her attacker is given credence when the severed breasts of the dead victims are discovered on Morton's premises and he is set for trial. He is defended by the formidable Corinna Maddox, known as 'Batwoman' for her tenacity, whilst the prosecutor is supercilious but wily Rupert Halliday, whose best line of attack is to work on Morton's cowed wife Cindy, who tolerated his young mistress being brought home and is doubtless providing a false alibi.

Walker is assigned to investigate the discovery of a 17-year-old skeleton, which he isn't too happy about - especially as he's working with D.I. North's ex-boyfriend. They soon discover more skeletons buried at the house.

A young school girl is raped and murdered, but D.C.I. Connor still has no leads a month into the investigation. When Walker orders a review of unsolved cases, they turn up similar cases of raped and murdered teenage girls over the last ten years, and they find themselves searching for an apparent serial killer.