The stories are often set in the English home counties "stock broker belt", but most episodes, especially from the second season onwards, feature at least one American character, mostly portrayed by an imported US guest star, to appeal to the American market. After originally being screened late night in the US under the ABC Mystery Movie billing from 1973, in 1978 some episodes were retitled for US syndication and all had additional opening sequences shot, with new titles and credits. Since these were made without the original cast they often feature menacing figures seen only from the neck down. The original replaced original UK and US title sequence featured a sequence of shots through a fisheye lens, bordered in bright red.

Starring:

Anthony Dawes, Bradford Dillman, Derek Francis, Derek Smith, Dinsdale Landen, Donna Mills, Edward Judd, Gary Collins, Geoffrey Chater, Harold Bennett, Ian Bannen, Ian Redford, Joanna Pettet, John Carson, John Flanagan, John Moreno, Linda Liles, Michael Jayston, Michael Kitchen, Michael Stainton, Norman Mitchell, Pamela Franklin, Patrick Magee, Peter Hill, Peter Mackriel, Ray Marioni, Reg Lye, Robert Powell, Ronald Mayer, Stephen Greif, Suzanne Neve, TP McKenna

Genre:

Crime, Mystery, Thriller