DCI Tony Clark finds himself assigned the unenviable task of investigating his own station when Scotland Yard suspects corruption. His first target is a ring of officers who are taking kickbacks from laundered drugs money.
When a youth is shot by police on a troublesome estate, years of resentment within the community flare into violence, to the concern of Chief Supt. Jameson.
A complaint of sexual harassment by a W.P.C. against a black sergeant, and an accusation of bribery, reveal widespread prejudice within a station. With his own personal life in tatters, is Det. Supt. Clark the right man to investigate the case?
Det. Supt. Clark follows up an allegation of police brutality after an old man claims to have seen a prostitute attacked, but an influential detective ensures that the enquiry is obstructed.
Det. Sgt. Connell's cover is blown while investigating a hostile police station. Det. Supt. Clark is caught up in a murder case with both personal and professional implications.
Clark and his team visit Liverpool to investigate an armed robbery conviction. A confession may have been beaten out of the robber, and a local reporter has an axe to grind.
Tensions rise on a picket line leaving Clark to discover who is responsible for serious injuries. Hard evidence is in short supply and old loyalties muddy the waters. Meanwhile, Clark's personal life is heading rapidly downhill.
Det. Supt. Clark is ordered to investigate outstanding complaints against P.C. Norton, an officer killed in the course of his duty. Should PC Norton be allowed to rest in peace?
Det. Sgt. Markham is accused of taking a bribe. Meanwhile, Clark's lover, W.P.C. Jenny Dean, is under pressure over her part in the Michael Carswell affair.
Det. Supt. Clark is caught between Customs and Excise and the river police during a case of extortion, drug smuggling and illegal immigration. W.P.C. Jenny Dean finds herself under investigation over her part in the Michael Carswell case.
A youth dies in police custody, but was it really a suicide? Det. Supt. Clark learns some uncomfortable truths about girlfriend W.P.C. Jenny Dean.
A police superintendent is caught kerb-crawling in King's Cross. Det. Supt. Clark uncovers murder, blackmail and pornography, and his investigation could finish some careers. The investigation into the Michael Carswell case has tragic consequences for W.P.C. Jenny Dean.
Commander Huxtable has been suspended. Det. Supt. Clark is determined to discover why his lover, W.P.C. Jenny Dean, committed suicide, but his enquiries lead back to C.I.B. Finally, he confronts an unexpected enemy aboard H.M.S. Belfast.
John Deakin is on trial, and Tony Clark is now Acting Detective Chief Superintendent. A high flying young officer, who has gone under cover to infiltrate a fascist organisation, appears to go native.
Supt. David Lindsay admits killing his wife, but claims it was manslaughter. Det. Sgt. Connell is convinced he's rigged the circumstances in order to walk free.
Clark and his team are called in to investigate when a black youth is killed in a hail of police bullets, and are soon caught up in conflict between the police and the local community. Their investigation draws them into the world of crack cocaine dealing.
A high profile M.P. is caught with his trousers down, and suspicion falls on his police protection officers. As more revelations appear in the tabloid press, Clark suspects a smear campaign.
An intruder is shot dead at a Territorial Army base. Clark is forced to accept help from Angela Berridge, an official from the Home Office, and finds that the activities of MI5 and Special Branch undermine his investigation.
A peaceful demonstration about council service cuts goes tragically wrong when the mounted police are called in to disperse the demonstrators. Clark's team is brought in but their activities are hindered by the chief constable heading the investigation.
An assistant chief constable is accused of sexual misconduct, and Det. Sgt. Connell's friend Kate is implicated. Det. Supt. Clark's search for a missing tape brings him back into contact with Angela Berridge.
Chief Supt. Trevor Dunne, recently cleared by an enquiry, faces another when a convicted criminal provides fresh evidence. Det. Supt. Clark is torn between duty and loyalty towards a highly regarded officer.
Det. Sgt. Connell's professional and private lives come into conflict when CIB investigate a police officr suspected if being the driver involved in a tragic hit-and-run incident. Det. Supt. Clark, meanwhile, is becoming increasingly obsessed with Angela Berridge.
Det. Insp. Naylor faces a disciplinary hearing when he is caught moonlighting for a security firm to raise funds for the treatment of his terminally ill wife, Joyce. Det. Supt. Clark confronts Angela Berridge over their relationship.
Det. Supt. Clark investigates the involvement of Special Branch in the 'execution' of police informant Declan Harris, and gets the chance to settle old scores with Det. Chief Supt. John Deakin.
Det. Supt. Clark is gunning for Det. Chief Supt. John Deakin, now with Special Branch, and is led to Trevor Bull, a victim of a police shooting years earlier.
Having sacrificed his career in the Met, Clark ponders what to do next, until Deakin pays him a visit - and asks him to travel to Tunisia to help a tabloid newspaper substantiate a story about an MP's private life.
Naylor struggles to regain his composure following the death of his wife. Meanwhile, Connell's career in the Met hangs in the balance, and Clark accepts his first investigation after delving into the world of espionage.
Deakin asks Naylor and Clark to track down a missing person.
Connell calls upon Clark and Naylor for help after falling into difficulty with a client.
Clark takes on the task of providing protection for a Chilean general, who has been receiving death threats.
Connell goes undercover to find out who is setting fire to a chain of fur shops, while Clark fears for Naylor's safety after he accepts a job working for a dodgy pharmaceutical company.
Clark investigates when a computer engineer from the defence industry is found dead in his garage, and ignores Deakin's warning to steer clear of the investigation.
Clark and Naylor set up a profitable arms job, but Connell wants in on the action - but the pair are convinced that it's too dangerous.
Clark is asked by Deakin to go undercover as a gun runner for a major neo-fascist rally in Belgium, posing as a right-wing arms dealer.
Clark and Naylor are blamed for failing to stop an arms shipment heading for Northern Ireland, but realise that they have been double crossed when Connell reveals she is still working for the police - and has offered up her two former colleagues for a promotion. Trapped on a boat that is about to implode, will Clark and Naylor make it out alive?