“When a case proves too baffling for the minds of Interpol, they turn to the talents of Department S.“

Department S was a United Kingdom spy-fi adventure series produced by ITC Entertainment. The series consists of 28 episodes which originally aired in 1969–1970. It starred Peter Wyngarde as author Jason King (later featured in spin-off series Jason King), Joel Fabiani as Stewart Sullivan, and Rosemary Nicols as computer expert Annabelle Hurst. The trio were agents for a fictional special department (the “S” of the title) of Interpol. The head of Department S was Sir Curtis Seretse (Dennis Alaba Peters).

Department S was a section of Interpol with an office in the Paris headquarters that investigated international cases other crime agencies were unable to solve. Sir Curtis Seretse, an international bureaucrat, was in charge of the team.

Stewart Sullivan was the head of Department S, taking instruction from Seretse. Sullivan did much of the leg work, confronting the criminals. Jason King was the ideas man, but also helped in the field. King was often seen with beautiful women before being called in on an assignment but had no permanent love interest in the series. King’s sideline was as an adventure novelist. He managed to use details from their cases to write his novels. A playboy with a woman in every city, he had once been married to a woman named Marion who had died in a plane crash (episode A Fish Out Of Water).

Annabelle Hurst was a computer expert taking an analytical role in investigations. However she also went on assignment as a conventional investigator, sometimes appearing in many seductive, glamorous disguises. There were hints of romantic interest between Sullivan and Hurst.