The series starred Stuart Damon as Craig Stirling, Alexandra Bastedo as Sharron Macready and William G...展开aunt as Richard Barrett. The characters are agents for a United Nations law enforcement organization called "Nemesis", which is based in Geneva. The three have different backgrounds and skills: Barrett is a code breaker, Stirling a pilot, and Macready a scientist and doctor.
During a mission, their plane crashes in the Himalayas and they are rescued by an advanced civilization living secretly in the mountains, who save their lives, granting them superhuman abilities in the process. The powers now possessed by the three heroes include the ability to communicate with one another over long distances by ESP (mental telepathy), and the ability to foresee events (precognition); they also have enhanced senses and reasoning power, and physical abilities up to the extent of human limits.
Many of the stories featured unusual villains, such as fascist regimes from unspecified South American countries, neo-Nazis or the Chinese. The villains' schemes often threaten world peace in some way—Nemesis's brief is supposed to be international, so the agents deal with threats that transcend national interests and concerns. One feature of the series was that the main characters had to learn about the use of their new powers as they went along.
The only other series regular, Anthony Nicholls, played the Champions' boss, Tremayne. Tremayne does not openly acknowledge that his agents have acquired special abilities, though he does on occasion ask mock innocent questions about how they have carried out specific tasks while on missions.