Callan (TV series) is run by Colonel Hunter. ("Hunter" is a pseudonym for the current Section Chief, like the C of SIS.) The Section removes those who pose a danger to the "innocent" by persuasion, blackmail, extortion or death. David Callan had been the Section's top operator but he had become too curious about his targets and the rationale for their removal. The Section considered him vulnerable, volatile and dangerous and had laid him off to a dead-end book-keeping job for an ungrateful employer. ABC then commissioned a series of six episodes in 1967. In the first episode Callan rejoins the section in
Callan (TV series) Prisoner", it is clear that Robert McCall (dubbed "Equalizer" by a fellow operative) is not related in any way to Callan. Though the characters do share some similarities, McCall had retired from an American intelligence agency whereas Callan had been terminated from a British one, and other backstory elements (including a failed marriage and a son (William Zabka) in his early 20s) eliminate any possibility that Callan had become McCall. That said, there clear echoes of Callan in Woodward's portrayal of McCall, such as an early episode where a female character encounters McCall in emotional distress after having to kill