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.

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.

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.

A spy is extradited to Britain with an attempt to keep his arrival top-secret. However, the Bulgarians from Batak's homeland who sent him appear to be trying to make his movements as public as possible. When he is eventually murdered, CI5 suspect his music student daughter of poisoning him.

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.

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.

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.

Bodie and Doyle are shocked to discover that Cowley appears to be selling nerve gas to a group of East Germans in order to line his own pockets, and are assigned by his rival Plumb to track their boss's every move.

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.

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.

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?

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.

CI5 move in to protect the daughter of a South American President after his son - and her brother - is assassinated on the field of a polo match.

Silver bullion is being shipped into Britain via the Iron Curtain, only for it to be hijacked by one of the group's own officials.

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.

A leader of a criminal gang offers to surrender himself if in exchange he is guaranteed protection for his family.

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.

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 suspect being held under CI5's supervision is found dead in his cell - apparently after a fatal blow administered by Doyle. A public inquiry ensues and an influential lawyer calls for CI5 to be shut down. It's left to Cowley in fighting to save the organisation he founded.

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 CIA agent is murdered in London, prompting CI5 into launching a fake arms deal with the terrorists who were responsible for the killing. But the gang uncover the plot in time, taking Bodie hostage and using him as their meal ticket to escape the country.

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 and Keller, an old acquaintance from his days in the SAS, go undercover in order to trap a would-be assassin by posing as hitmen offering to do the job themselves - in order to fake the killing. But Keller turns out to have an ulterior motive.

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.

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.