An Iron Curtain agent is using a young girl to extort secrets from, and ultimately destroy the career of, a future British Prime Minister, unaware that the girl is the long-lost daughter of a well-known local prostitute.

A dying man's confession triggers the re-opening of a twenty-year-old case of police corruption, an investigation in which the main prosecution witness was murdered by the police officers who were supposedly trying to protect her. Somebody then decides to silence these officers, and sets about doing so.

Charles Nesbitt, an expert on chemical weapons, threatens to contaminate the water sources of London with a lethal hallucogenic drug and in order to back up his claims, plans several small 'demonstrations' in warning to the local authorities - including CI5.

On leave from CI5 with a hand injury, Bodie takes a day trip with his girlfriend and finds himself face-to-face with the leader of a terrorist group. He captures him but then the rest of the gang arrive and trap Bodie and his girlfriend in a nearby vicarage, leaving him unable to alert his colleagues back at CI5 HQ. With barely any clues as to his whereabouts, Doyle and Cowley go on a chase through the countryside to try and locate Bodie.

A gangster called Turkel devises a plot to free his brother from jail by taking hostage an important figure in authority. He is unaware, however, that the 'important figure' he has taken in is actually Cowley masquerading as the Home Secretary, with Bodie as his bodyguard and Doyle ready to pull the trigger on Turkel's brother.

Cowley finds himself under suspicion when a former colleague of his is arrested for being a double agent. So just how deeply involved is the CI5 Chief?

CI5 and their agents find themselves under attack from a vendetta of bombings and assassination attempts. Bodie and Doyle are on a chase to find out who the perpetrators are before they end up as the next victims.

Bodie is out at a restaurant with his girlfriend when a bomb goes off at their table, leaving her critically injured and several other diners dead. It's left to Bodie to find out who targeted him and why - until he realises he wasn't the target after all.

Cowley assigns Doyle to test a brand new high-tech laser beam rifle. But the rifle is stolen from his flat and the thief decides to 'test' it on Doyle, sending him on a cat-and-mouse chase around London.

CI5 become aware that an assassination plot on a group of visiting Greek Royals is being planned using a rifle that has a range of over two miles. But they must find out who is the gunman and what is his target - before it is too late.

A former colleague of Cowley's who is now a patient in a mental hospital reappears in London, going on the run when he believes that the KGB have drugged him.

Various industrial secrets and highly-valuable arts treasures are being stolen and sold on by a gang who are using the blind routine of Customs to their full advantage. CI5 devise a trap to stop the thieves in their tracks.

Bodie and Doyle are undergoing intense training in preparation for an assignment where they are protecting a foreign official...at the same time, two potential killers are receiving similiar training to prepare them for the assassination of the same official.

A team of Hong Kong police join CI5 in London to help crack a local heroin supply and protection racket. It's down to Bodie and Doyle to expose a scheme to smuggle drugs to the US by teams of Triads and European agents.

A virtual police state has been imposed by a local Chief Constable, resulting in a supposedly almost crime-free city. But that is because all the crime is taking place behind the scenes by the police officers themselves - who will think of nothing of imposing on suspects' rights in their pursuit of 'zero tolerance'. Bodie and Doyle become hunted men when they visit the city and begin to question the rather unorthodox methods of action taken by the local constabulary.

Cowley is offered the name of a highly-placed double agent from an old colleague - who in return wants to be guaranteed protection with CI5. This leads to the start of a dangerous stand-off between the two, using Bodie and Doyle as the pawns.

In the midst of a shoot-out during a drugs smuggling investigation, Doyle meets and falls for Ann Holly, only to discover that CI5 suspect her of being closely linked to the scam herself.

Bodie's mental state is called ino question when he becomes obsessed with a local Hell's Angel motorcycle gang, gradually sending him further and further behind in training. Is he cracking up?

An organisation which hires killers to assassinate virtual nobodies on sight is infiltrated by Bodie and Doyle, who must find out who the perpetrators are and why, by going undercover and posing as potential hitmen themselves.

An attempt to start up a street war is launched by a gangland breakaway opposition group, but their leader appears to have an ulterior motive in his actions.

Annie Irving, an extreme left-wing preacher - and former flame of Cowley's - becomes the target of a hitman when one of her meetings comes to London. Cowley assigns Bodie and Doyle to protect her, unaware that the would-be hitman is right under his nose.

It's just another routine house break-in for a cat burglar, until he accidentally uncovers a complex drugs smuggling operation. When CI5 step in, they realise it's not just the burglar's life that is now in danger.

A drug addict is murdered by a pusher who then hastily discards the gun, only for it to be found by a young boy-who then accidently shoots his friend in the process. The pusher then goes in search of the boy in an attempt to retrieve the gun and at the same time has to try to avoid his own people who are in pursuit of him.

Bodie, Doyle and their latest girlfriends are on a quiet weekend in the country when they unwittingly get caught up at a farmhouse siege in which they must try and escape from a group of gun-toting fugitives.

CI5 manage to undercover a series of financial blunders between a group of builders and council officials after a site of newly-built houses on a council estate are found to be crumbling.

A post-operative ward in a hospital is held to ransom by a newly-released convict who plans to make a fortune, setting up his own foxhole at the top of a nearby building. CI5 hatch a plot to bring him down before he takes a fatal shot at the hospital.

A dummy run that has been staged for the visit of a Middle Eastern official is found to have been recorded by a foreign student, subsequently leading CI5 to suspect a security leak.

A hitman is employed by a group of East German officials to assassinate a reporter who is planning to publish a report in which their new fighter plane is branded as a potential death-trap.

A young woman from a rich and successful family turns terrorist, shunning her wealthy background and the British Justice system which she now views as being corrupt. Important legal establishments located around London are targeted by the terrorist groups, who are planting several bombs at key points around the city.

A British traitor returns to his homeland and must be found before his former colleagues, seeking vengeance for his past betrayals, go in search of his whereabouts.

Bodie and Doyle are assigned to protect a foreign official who is on a secret visit to Britain. But already possible enemy assassins appear to know his - and CI5's - every next move.

When a newspaper takes it upon themselves to irresponsibly publish a list of the names of witnesses to an assassination, it is left to CI5 to not only protect these people, but at the same time apprehend the killers before they strike again.

CI5 are left to dig deep when an Israeli Minister is kidnapped, and the only clues to his whereabouts are a shadowy photograph and a coded tape message.

Years after a man's wife died and his child left brain-damaged following a series of blunders at the hospital they were treated at, he returns to finally seek revenge by systematically assassinating each of the same hospital's medical staff one-by-one.