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
Michael Callan "Marooned" (1969). After eight years and 13 films with Columbia, Callan landed the lead role of Peter Christopher in the NBC Television sitcom "Occasional Wife" made by Columbia's Screen Gems. At the time, Callan was married to the former Carlyn Chapman. The young couple lived in Beverly Hills and had two daughters. He engaged in a 12-hour day filming schedule with weekends off for the production of the half-hour television series. Callan divorced Carlyn and was married for a time to Patricia Harty, the actress who played his "occasional wife" in the series. In 1968, he co-starred as 'Bill Calhoun'