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.

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 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.

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.

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.

A group of former comrades from Bodie's mercenary days reappear in England and in order to impress a top London gangster, carry out a violent raid on a local bank. It's left to CI5 to catch and stop the ringleader Krivas and his gang, reuniting Bodie with some of his old adversaries in the process.

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.

The daughter of a man inprisoned by Doyle six years ago when he was a Docklands policeman turns up, claiming to have new evidence which will exonerate her father. Doyle reluctantly agrees to reopen the case, but will his budding relationship with the girl cloud his judgement, and make even himself doubt whether he jailed the right man?

A CI5 agent is murdered, leading to the discovery of a man who is dying as a result of plutonium poisoning. This links CI5 to a further plot involving the imminent explosion of an A-bomb at the same bowling alley. It's left to Bodie and Doyle to try and de-activate the fuse before it takes them and the whole of London with it.

CI5 are assigned to protect a visiting American Ambassador from a renowned hitman called Ramos, who is hot on his trail. But after only one apparent assasination attempt at his life, Ramos appears to give up - only for him to turn up again at CI5 HQ itself.

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.

Members of a 'Keep Britain White' group go on the rampage in London, attacking the local black residents in an attempt at forcing them to leave the area...but two of the group members have an ulterior motive. Bodie is left seriously injured whilst Doyle joins the group undercover.