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.

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.

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.

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.

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 is re-acquainted with a former girlfriend when she shows up in London, and during a secret meeting with her finds himself framed for an assassination and then ultimately on the run from his own colleagues at CI5.

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.

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 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.

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.

The daughter of a British Government engineer who is working on a defence protect is kidnapped, and the only way she will be safely returned is if he agrees to betray secrets to enemy agents.

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.

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.

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.

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.

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.

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 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 department in a British Government appears to be attempting to kill a bunch of drug-dealing students...but why?

Bodie is offered the opportunity to clear up all his gambling debts by a foreign diplomat - who in exchange wants to have some vital secrets from CI5.