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

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

Callan apparently turns renegade. A ruse to trap the head of a ‘pipeline' for smuggling foreign agents and defectors out of the country.

Callan must use the wife of a rocket scientist as bait to lure the same scientist to Britain.

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

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

Callan must retrieve a microfilm from a spying medium.

Calln must find everything out about the past of an influential politician.

The French O.A.S. carry an internal war into England. Callan and Meres must sort out the mess.

Callan and Meres must catch the controller of a ring of spies before he can leave the country with the information the ring has gathered.

Callan and Meres must secure the safe of a ship that was sunk during World War Two. It contains a list of Third Reich collaborateurs and puppets. A survivor of the ship tries to stop them.

Callan must stop fashist agitators from killing the Chinese Ambassador.

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.