Security wants a retired brigadier of the British army to be stopped from accepting a job offer from a sultan, deadly force is requested.

Callan in brainwashed into believing that Hunter is the leak in the Section and that he has also killed Lonely and framed Callan for murder. In his drugged state Callan kills Hunter and is shot down by Meres.

Callan tracks down Richmond who is trying to leave Britain.

A freelance German mercenary organisation who specialise in eliminating foreign security sections have their sights set on the Section.

Lonely becomes the unlucky witness to a mob hit.

Callan debriefs a top enemy defector.

The Section's new Hunter has Callan pulled from the field.

Hunter's secretary, Liz, is out for someone's blood.

Callan and Cross must break a Russian spy out of prison, where he has voluntarily surrendered himself to, and kill him.

Lonely is used as bait to retrieve Callan from the KGB.

Callan has become the new Hunter. And his first job is to retrieve a list of British undercover agents.

Callan looses his position as Hunter when he goes after the assassin who killed Cross.

Callan and Lonley break into a courier's house to find out how he's operating.

Callan must prove that a young biochemist is not giving information to the East.

After Hunter's death Meres and Calln must fetch the new Hunter from East Germany.

Richmond, a top enemy defector, reveals his true purpose.

Callan helps a former agent out of a blackmailing business.

Hunter, head of the Section, requires the services of his best operative, David Callan. Callan had been 'retired' from the service due to his growing conscience, disrespect for orders, and concerns about the people he was ordered to eliminate. Callan now working as a bookkeeper, a job he despises, is offered to be reinstated into the Section if he kills Schneider, an international arms dealer.

Hunter wants Callan to stop a blackmailing Lord from selling the negatives used in the blackmail to all and sundry.

Callan is assigned to disrupt a romance between a government worker and a suspected spy. Reluctantly he delves into his bag of dirty tricks.

Callan is dead. Or so the KGB would have you think.

Callan tries to quit the Section when a girl he is seeing takes a dislike to his job.

The new Hunter cannot decide if Callan is to return to the Section or not.

When Cross kills an innocent bystander it's up to Callan to cover for him, but even he cannot decide if it was an accident or murder.

An exchange of captured agents with the Soviets goes sour.