Dangerous Knowledge

TMDB score: 8.0/10

A gritty six-part mystery thriller serial from 1976, starring John Gregson as Bill Kirby. Bill is an insurance salesman travelling back to the UK from France. Accompanied by Laura Marshall (Prunella Ransome), he has to evade the two armed agents that are following him. A series of murders follow and Bill tries to unmask who's behind them.

Selected season 1, episode 1.