The Baron - Season 1 Episode 13 Portrait of Louisa

Louisa Trenton, an old friend of Mannering is in trouble. When she sells the Baron some rare family miniatures he offers his help but she declines. Later when she calls for his help he rushes to meet her in a London club only to find that she has been murdered. When he investigates he discovers that she was being blackmailed by her young lover. He is only the fall guy but as Mannering tries to find out who is the boss, more people are murdered.