A man is released on licence after serving 20 years for the murder of a 14-year-old girl. When the body of her best friend, who disappeared at the same time, is found, Frost has to investigate a 20-year-old murder.

A bus driver and conductress are abducted. Frost is unhappy at being paired with DS Marsh, who made a complaint about him 15 years before.

Frost's Saturday afternoon is disrupted by the discovery of a man's body floating in the river, and it turns out that he is not who he claimed to be. Events become more intriguing when the star player of a local soccer team collapses during a press conference, following an incident on the pitch in which he received head injuries.

A ruthless kidnapper holds a supermarket chain to ransom by threatening the life of a young boy.

A woman commits suicide naked in public, and Frost connects her death with the later death of a gigolo. He discovers that the dead man had business with several women in Denton. Meanwhile there appears to be a series of break-ins at the local cricket pavilion, and Supt Mullett, who is a member, orders Frost to investigate them as well as the murder.

Frost investigates an MP's son who is involved in a hit-and-run accident, and a robbery at a private casino, which occur on the same night. He gets a humorless new partner to assist him.

Nursing his terminally-ill wife, Det Insp ""Jack"" Frost's life becomes more stressed when, during a missing-child investigation, he unearths evidence on a 30-year-old case involving a skeleton chained to a locked strongbox that turns out to be empty.

A young woman is found viciously stabbed to death. Frost consults the victim's personal organiser, from which a trail leads him to a religious community.

Frost's house is burned down, and he moves in with a colleague temporarily. A mysterious, ruthless kidnapper on a motorcycle tests Frost's skills to the limit. It proves a tough case to crack, and for the abducted woman, time is running out.

A man's church confession provides an insight into what appears to be a straightforward murder. But before Frost can make an arrest, he is suspended over the outcome of a related case 10 years earlier.

Frost continues to try to identify the detective's killer. The task is complicated by a bizarre series of pet shootings, about which he is reluctantly forced to seek help from a computer system run by a seconded new junior WPC. His pursuit leads to a confrontation high above a power station.

Denton's last remaining quarry is vandalised. Frost finds a baby in his office and is delighed to discover it belongs to DS (previously WPC) Hazel Wallace. He gets Hazel to look into some burglary's that have been occuring just after removal jobs have been completed. At the quarry a second body is found, which causes them to call the police. The only witness to the murder is an autistic boy, who immediately becomes prime suspect. Frost finds out about some dodgy dealings in the past between the quarry owner and his former partner. The boy escapes through a window and the Officers on duty get a sever telling off. A woman comes in saying her 7-year-old son has been abducted by her husband. The quarry owner then turns up dead in a brook a small way from the quarry. The boy is found but he has rigged the Autistic boy is found and he has rigged Denton Quarry with explosives and threataning to blow the quarry and himself up. Frost manages to get the boy down but the explosives in the boy's bag still explode. Frost then goes and arrests the quarry owner's partner for the double murder and finds the other boy safe and sound in a removals depot. He arrests the missing boy's father for robbery.

Frost investigates the murder of a teenage girl, and the case of a woman who has been receiving threatening phone calls. Meanwhile, at the Denton police station, there are threats, deaths, arson and a staff shortage.

An odd group of animal rights advocates attempting to sabotage a foxhunt includes a working-class teenager, who is murdered. Then another person associated with the anti-hunt protesters is murdered. His investigations take Frost to tea with a local squire, but Supt Mullett is apprehensive lest he upset the gentry.

There is an armed robbery at a local family-run glassworks, in which an employee is shot dead. The owner, who is one of the witnesses, is then threatened, and goes into hiding. The family has a tangled web of personal relationships, which Frost has to understand, in order to find who is doing the threatening. Meanwhile, Shirley Fisher's mother dies, and he fails to attend the funeral. DS Lawson lets business and personal relationships mix, with serious consequences.

Frost is held at gunpoint by a drugs dealer, a Territorial soldier is shot dead on an exercise, and a security van is robbed by a shotgun-wielding gang. Frost investigates the three incidents, and tries to find any links between them. His intrusions onto the army base stir up hostility from the commanding officer.

Frost is assigned a new, West Indian detective constable, Clive Tanner; transferred in to help him investigate a string of commercial burglaries, which leads him to a black family on the local Eastdean estate, that he calls ""the crime academy"", while feeling guilt over the death of one of his informants. Will the arrest of the apparent culprit lead to accusations of police racism?

While Denton´s female population has to watch out for a con man posing as Frost, Frost himself has more dire concerns: a woman found dead by the railroad. To top it off, Frost has to work with a soon-to-be wash-out with possible drug problems. Then a disliked surgeon goes missing, and turns up dead.

Upon investigation, Frost discovers that the apparently accidental death of a drug addict was actually murder. He also decides to confront an aspect of his own past.

Frost responds to a call for help but, when he arrives at the scene, all he finds is a disembodied leg… and a crocodile!

Frost investigates a series of break-ins and brutal attacks at the homes of elderly people. He is helped by a female detective, DS Lawson, who also offers him advice on his personal life.

An 8-year-old girl is missing, and the last person to have seen her is Billy Conrad, a gentle young man with Down's syndrome, but who appears is hiding something.

Hazel Wallace returns from her training, as the new Detective Sergeant, and is put to work by Supt Mullett sorting out the mess left behind by DI Frost, while he is on extended compassionate leave. Before long she is called upon, when a man is found hanged in his home, and she suspects it was not suicide. Routine investigations show that a fresh set of fingerprints at the scene belong to an unidentified man who had been found drowned a year previously. Frost is summoned back by Supt Mullett to sort things out, and he connects a painting that appears to have been stolen from the hanged man with an art robbery & murder some years before.

After a seven-month long suspension, Frost is back on the job. His first case is a floater in Denton River, with £6000 in his pockets. The man also carries with him a list with four sets of mysterious numbers, and the keys to two different cars. The local dance competion is the venue for another drama: a missing con man who recently switched dance partner, and a woman with a Hollywood name and a terrible temper - who keeps on ordering new fridges for her dance partners... But Frost is more interested in getting his teeth back in order after a particularly vicious lollipop.

A woman is found in a critical condition in a quiet village on the outskirts of Denton, a victim of an apparent hit-and-run incident. Her husband and daughter are distraught. Frost's investigation exposes the secret life of a corner of rural England.