CALLAN - Series 4 - Episode 1 - That'll be the Day
Introduction
David Callan is the top agent/assassin for the S.I.S. (British counterintelligence), but he is an embittered man who performs his duties "for Queen and country" under duress. This bleak, "Spy who Came in from the Cold"-style espionage drama concentrates on the seamy underside of covert operations: assassinations, blackmail and dirty dealing.