The series starred Stuart Damon as Craig Stirling, Alexandra Bastedo as Sharron Macready and William Gaunt as Richard Barrett.
The characters are agents for a United Nations law enforcement organization called "Nemesis", based in Geneva.
The three have different backgrounds: Barrett is a code breaker, Stirling a pilot, and Macready a recently widowed scientist and doctor.

Original Run:September 25, 1968 to
April 30, 1969